The routine use of diagnostic laparoscopy in the intensive care unit.

BACKGROUND: Delay in the diagnosis of intraabdominal pathology is a major contributor to the morbidity and mortality of intensive care unit (ICU) patients. Laparoscopy is a valuable diagnostic tool that can be used safely and efficiently in the evaluation of intraabdominal processes that may be difficult to diagnose with conventional methods. Our goal was to show that laparoscopy performed at the bedside in the ICU could be used as a routine diagnostic tool in the evaluation of critically ill patients, just as computed tomography (CT), ultrasonography (US), and radiography are. METHODS: We present 11 patients who underwent 12 bedside examinations in the ICU of a community teaching hospital. Several different surgeons with varying degrees of laparoscopic experience performed these procedures over a 1-year period. RESULTS: Four patients had previously undergone recent abdominal operations. Nontherapeutic laparotomy was avoided in six patients because of diagnostic laparoscopy. One patient also underwent a therapeutic maneuver at the time of diagnostic laparoscopy. None of the patients required general anesthesia, although local anesthetics and sedation with midazolam or propofol were used. One patient underwent the procedure without endotracheal intubation. There were no complications or mortalities directly related to the procedure. CONCLUSION: We conclude that bedside laparoscopy in the ICU under local anesthesia is a diagnostic and potentially therapeutic tool that can be used safely in the work-up of potential abdominal pathology in critically ill patients.

Structure and functional characterization of a novel human low-voltage activated calcium channel.

We have isolated and characterized overlapping cDNAs encoding a novel, voltage-gated Ca2+ channel alpha1 subunit, alpha1H, from a human medullary thyroid carcinoma cell line. The alpha1H subunit is structurally similar to previously described alpha1 subunits. Northern blot analysis indicates that alpha1H mRNA is expressed throughout the brain, primarily in the amygdala, caudate nucleus, and putamen, as well as in several nonneuronal tissues, with relatively high levels in the liver, kidney, and heart. Ba2+ currents recorded from human embryonic kidney 293 cells transiently expressing alpha1H activated at relatively hyperpolarized potentials (-50 mV), rapidly inactivated (tau = 17 ms), and slowly deactivated. Similar results were observed in Xenopus oocytes expressing alpha1H. Single-channel measurements in human embryonic kidney 293 cells revealed a single-channel conductance of approximately 9 pS. These channels are blocked by Ni2+ (IC50 = 6.6 microM) and the T-type channel antagonists mibefradil (approximately 50% block at 1 microM) and amiloride (IC50 = 167 microM). Thus, alpha1H-containing channels exhibit biophysical and pharmacological properties characteristic of low voltage-activated, or T-type, Ca2+ channels.

Use of unproven therapies by people with Alzheimer's disease.

OBJECTIVE: To describe the use of unproven therapies for Alzheimer's disease. DESIGN: Descriptive survey using a written questionnaire. PARTICIPANTS: 101 primary caregivers of people with Alzheimer's disease who attended Alzheimer's disease support group meetings. RESULTS: Fifty-five percent of caregivers reported that they had tried at least one alternative therapy to improve the patient's memory. Twenty percent of caregivers tried three or more unproven therapies. Vitamins were used most frequently (84%), and health foods (27%), herbal medicines (11%), "smart pills" (9%), and home remedies (7%) were also tried. Most caregivers reported trying the therapies in the early stage of the illness and did not notice significant improvement in the patient's memory. Twenty-five percent of caregivers had tried unproven therapies for behavior problems. There was no correlation between the use of alternative therapies and the sex of the caregiver, age of the caregiver, level of caregiver frustration, presence of problem behaviors, or perceived level of physician support. CONCLUSIONS: The use of unproven therapies by people with early Alzheimer's disease is common and cannot be predicted by characteristics of the primary caregiver. Although this use may be understandable, it exposes vulnerable people to possible side effects, increased costs, and possible exploitation. Health care workers should actively inquire about the use of alternative therapies, and explore the reasons behind their use, so that they can better understand and meet the needs of their patients and their caregivers.

Targeting the maize T-urf13 product into tobacco mitochondria confers methomyl sensitivity to mitochondrial respiration.

The URF13 protein, which is encoded by the maize mitochondrial T-urf13 gene, is thought to be responsible for pathotoxin and methomyl sensitivity and male sterility. We have investigated whether T-urf13 confers toxin sensitivity and male sterility when expressed in another plant species. The coding sequence of T-urf13 was fused to a mitochondrial targeting presequence, placed under the control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Plants expressing high levels of URF13 were methomyl sensitive. Subcellular analysis indicated that URF13 is mainly associated with the mitochondria. Adding methomyl to isolated mitochondria stimulated NADH-linked respiration and uncoupled oxidative phosphorylation, indicating that URF13 was imported into the mitochondria, and conferred toxin sensitivity. Most control plants, which expressed the T-urf13c construct lacking the mitochondrial presequence, were methomyl sensitive and contained URF13 in a membrane fraction. Subcellular fractionation by sucrose gradient centrifugation showed that URF13 sedimented at several positions, suggesting the protein is associated with various organelles, including mitochondria. No methomyl effect was observed in isolated mitochondria, however, indicating that URF13 was not imported and did not confer toxin sensitivity to the mitochondria. Thus, URF13 confers toxin sensitivity to transgenic tobacco with or without import into the mitochondria. There was no correlation between the expression of URF13 and male sterility, suggesting either that URF13 does not cause male sterility in transgenic tobacco or that URF13 is not expressed in sufficient amounts in the appropriate anther cells.

Structure and functional characterization of neuronal alpha 1E calcium channel subtypes.

We have cloned overlapping cDNAs encoding alpha 1E Ca2+ channel subunits from mouse and human brain. We observed that these alpha 1E transcripts were widely distributed in the central nervous system. We also demonstrated the existence of two variants of the human alpha 1E subunit. Comparison of the sequence of these alpha 1E subunits to those from other species suggests that at least four alternatively spliced variants of alpha 1E exist. Expression of human alpha 1E in HEK293 cells and Xenopus oocytes produced high voltage-activated Ca2+ currents that inactivated rapidly (tau approximately 20 ms at 0 mV). The size of the currents obtained were enhanced approximately 40-fold by co-expression with human neuronal alpha 2 and beta Ca2+ channel subunits. alpha 1E currents were insensitive to the drugs and toxins previously used to define other classes of voltage-activated Ca2+ channels. Thus, alpha 1E-mediated Ca2+ channels appear to be a pharmacologically distinct class of voltage-activated Ca2+ channels.

Structure and functional expression of an omega-conotoxin-sensitive human N-type calcium channel.

N-type calcium channels are omega-conotoxin (omega-CgTx)-sensitive, voltage-dependent ion channels involved in the control of neurotransmitter release from neurons. Multiple subtypes of voltage-dependent calcium channel complexes exist, and it is the alpha 1 subunit of the complex that forms the pore through which calcium enters the cell. The primary structures of human neuronal calcium channel alpha 1B subunits were deduced by the characterization of overlapping complementary DNAs. Two forms (alpha 1B-1 and alpha 1B-2) were identified in human neuroblastoma (IMR32) cells and in the central nervous system, but not in skeletal muscle or aorta tissues. The alpha 1B-1 subunit directs the recombinant expression of N-type calcium channel activity when it is transiently co-expressed with human neuronal beta 2 and alpha 2b subunits in mammalian HEK293 cells. The recombinant channel was irreversibly blocked by omega-CgTx but was insensitive to dihydropyridines. The alpha 1B-1 alpha 2b beta 2-transfected cells displayed a single class of saturable, high-affinity (dissociation constant = 55 pM) omega-CgTx binding sites. Co-expression of the beta 2 subunit was necessary for N-type channel activity, whereas the alpha 2b subunit appeared to modulate the expression of the channel. The heterogeneity of alpha 1B subunits, along with the heterogeneity of alpha 2 and beta subunits, is consistent with multiple, biophysically distinct N-type calcium channels.

Relaxation, reduction in angry articulated thoughts, and improvements in borderline hypertension and heart rate.

An intensive 7-week relaxation therapy was evaluated in a sample of unmedicated borderline hypertensive men. All subjects were provided state-of-the-art medical information regarding changes known to affect hypertension favorably, e.g., lower salt intake and regular exercise. In addition, relaxation subjects were trained in muscle relaxation that entailed audiotaped home practice. As predicted, relaxation combined with hygiene lowered blood pressure more than did hygiene alone. Neither treatment favorably affected a paper-and-pencil measure of anger but relaxation did lower anger-hostility on a new cognitive assessment procedure, Articulated Thoughts in Simulated Situations (ATSS). Moreover, ATSS anger-hostility reduction was correlated with blood pressure or heart rate reductions, for all subjects and especially for those in the Relaxation condition. This represents the first clinically demonstrated link between change in a cognitive variable and change in cardiovascular activity. Finally, results were especially strong in subjects high in norepinephrine, suggesting its importance in essential hypertension.

Differential expression of two related organ-specific genes in pea.

We have screened a pea genomic library using a cDNA probe derived from pea shoot RNA. From this screen, we isolated two closely related genes, designated as S2 and P4. An intriguing property of these two genes is the presence in their coding region of a repeated sequence that is conserved between them in sequence but not in the number of the repeating units. The predicted amino acid sequence suggests that these proteins could be exported and glycosylated. 3' S1 analysis reveals that one of the genes, S2, is expressed highly in stem, as expected from previous work. However, mRNA derived from the other gene, P4, is not detectable in stem tissue, but is present in tissue derived from pea pods. The 5' upstream sequence of S2 and P4 are 94% identical up to position -121, suggesting that sequences upstream of -121 are responsible for organ-specific expression of the two genes.

Primary structure of the gamma subunit of the DHP-sensitive calcium channel from skeletal muscle.

Affinity-purified, polyclonal antibodies to the gamma subunit of the dihydropyridine (DHP)-sensitive, voltage-dependent calcium channel have been used to isolate complementary DNAs to the rabbit skeletal muscle protein from an expression library. The deduced primary structure indicates that the gamma subunit is a 25,058-dalton protein that contains four transmembrane domains and two N-linked glycosylation sites, consistent with biochemical analyses showing that the gamma subunit is a glycosylated hydrophobic protein. Nucleic acid hybridization studies indicate that there is a 1200-nucleotide transcript in skeletal muscle but not in brain or heart. The gamma subunit may play a role in assembly, modulation, or the structure of the skeletal muscle calcium channel.

Sequence and expression of mRNAs encoding the alpha 1 and alpha 2 subunits of a DHP-sensitive calcium channel.

Complementary DNAs were isolated and used to deduce the primary structures of the alpha 1 and alpha 2 subunits of the dihydropyridine-sensitive, voltage-dependent calcium channel from rabbit skeletal muscle. The alpha 1 subunit, which contains putative binding sites for calcium antagonists, is a hydrophobic protein with a sequence that is consistent with multiple transmembrane domains and shows structural and sequence homology with other voltage-dependent ion channels. In contrast, the alpha 2 subunit is a hydrophilic protein without homology to other known protein sequences. Nucleic acid hybridization studies suggest that the alpha 1 and alpha 2 subunit mRNAs are expressed differentially in a tissue-specific manner and that there is a family of genes encoding additional calcium channel subtypes.