Access to computers for older adults: problems and solutions

Activity that involves a personal computer is a valuable modality for the rehabilitation of older adults. The therapist without specialized training, however, may have difficulty integrating computer use with adults with chronic health problems that impede such use. The purpose of this paper was to describe positioning, visual access, and input problems that may interfere with computer access and to identify solutions for use by the occupational therapist. Through a review of occupational therapy and adaptive computer literature, resources for adaptive computer hardware, software, and positioning devices are identified. Examples of how computer activities can be integrated into existing nursing home, day-care, and home-care programs are provided. Recommendations are made for training for the occupational therapist with limited experience with personal computers and adaptive computer technology.

Congestive cardiac manifestations from cerebrocranial arteriovenous shunts. Endovascular management in 30 children

Since 1984 we have been involved in the management of 30 children who had cardiac manifestations secondary to cerebrocranial arteriovenous shunts. Aneurysm malformation of the vein of Galen was the most common vascular lesion observed (73% of cases). In 77% of the patients the cardiac symptoms were the main presenting complaint. Medical treatment and/or endovascular therapy were indicated, depending on the age of the patients and the severity of the cardiac manifestations. Following embolization, the cardiac symptoms resolved (73%) or improved (18%) in 1 or 2 sessions. Mortality in the embolized group was 9%, and transient nonneurologic morbidity occurred in one case. Overall mortality, including four patients rejected for embolization, was 20%. These results compare favorably with medical and/or surgical management, alone or combined. The technique, challenges, indications and contraindications of endovascular therapy are discussed. Embolization represents an effective adjunct treatment to control, improve or cure the congestive cardiac manifestations caused by cerebrocranial arteriovenous shunts.

Atrial natriuretic factor (ANF) is a potent bronchodilator in asthma

The bronchodilating effects of atrial natriuretic factor (ANF) were compared to effects of salbutamol in a double-blind, placebo-controlled, crossover study in eight subjects with asthma and with airflow limitation. ANF was infused intravenously (0.1 microgram/kg/min during 30 minutes) and caused a short-lasting significant (p less than 0.012) bronchodilation in all patients similar in intensity to intravenous salbutamol (0.13 microgram/kg/min). The duration of the effect of the beta 2-agonist, however, was longer. No severe side effects were noted with ANF infusion. ANF may play a role in the modulation of the bronchial tone in humans, but its usefulness in the treatment of asthma remains to be determined.

[Anesthetic management for arteriographic evaluation and endovascular treatment in children with arteriovenous malformation of the vein of Galen]

In a series of 23 consecutive patients under 3 years old with VGAVM managed in Bicêtre from 1985 to 1990, 19 have been angiographically explored and 16/19 embolized (35 total procedures). Anaesthetic management must be adapted to the consequences of this disease: heart failure in newborns, intracranial hypertension in infants and the technical constraints of anaesthesiology in infants during neuroradiological explorations. Our results are satisfactory when compared to the classical bad prognosis of the disease: 90% of all the heart failures were ameliorated or cured; 10 infants are anatomically cured. The technical morbidity and mortality in embolized patients is nil. No perfusion breakthrough phenomena was observed in this series.

Use of suprathreshold test data to predict the results of quantitative testing in the nasal periphery

We compared the results of suprathreshold testing of the nasal periphery with those of quantitative assessment of the same area. One eye each from 81 patients in four categories (normal [21 subjects], low-risk ocular hypertensive [20 subjects], high-risk ocular hypertensive [20 subjects] and early glaucoma [20 subjects]) was tested with the nasal suprathreshold points of the Octopus G1 program and the Sargon peripheral field-nasal (PFN) program. Simple algorithms were developed to generate from the nasal suprathreshold points of the G1 program two "qualitative indices", mean defect-qualitative (MD-Q) and loss variance-qualitative (LV-Q); these are analogous to the indices mean defect and loss variance respectively, which were calculated from the PFN program data. MD-Q and LV-Q were found to be well correlated with their quantitative counterparts. They provide a uniform method for interpreting the nasal suprathreshold points of the G1 program and help identify patients in whom further quantitative testing is likely to yield useful information.

Molecular basis of lipid transfer protein deficiency in a family with increased high-density lipoproteins

Plasma high density lipoproteins (HDL) are a negative risk factor for atherosclerosis. Increased HDL is sometimes clustered in families, but a genetic basis has never been clearly documented. The plasma cholesteryl ester transfer protein (CETP) catalyses the transfer of cholesteryl ester from HDL to other lipoproteins and therefore might influence HDL levels. Using monoclonal antibodies, we show that CETP is absent in two Japanese siblings who have markedly increased and enlarged HDL. Furthermore, they are homozygous for a point mutation in the 5'-splice donor site of intron 14 of the gene for CETP, a change that is incompatible with normal splicing of pre-messenger RNA. The results indicate that the family has an inherited deficiency of CETP due to a gene splicing defect, and illustrate the key role that CETP has in human HDL metabolism.

Laryngospasm-induced pulmonary edema

Laryngospasm is one of the more common forms of airway obstruction encountered by an anesthetist. Therapy usually is straightforward, with resolution of the obstruction normally occurring within minutes. In some cases, however, the patient's vigorous inspiratory efforts may lead to a rapidly deteriorating form of pulmonary edema. Two cases are presented that are quite typical of the development of this complication. The etiology, recognition and management of this form of non-cardiac pulmonary edema is discussed.

Efficacy and safety of once-daily levobunolol for glaucoma therapy

We studied the ocular hypotensive efficacy and safety of 0.5% levobunolol hydrochloride and 0.5% timolol maleate administered topically once daily for 3 months in 91 patients (46 in the levobunolol group and 45 in the timolol group) with primary or secondary open-angle glaucoma or ocular hypertension. In this randomized double-masked parallel clinical study, intraocular pressure (IOP) was successfully controlled in 78% of the patients who received levobunolol and 89% of those who received timolol. The overall mean decrease in IOP was 5.6 mm Hg (decrease of 23%) in the levobunolol group and 6.7 mm Hg (26%) in the timolol group, a nonsignificant difference. In both groups the overall mean IOP during treatment was significantly lower than the pretreatment value (p less than 0.001). For both treatment groups changes in heart rate and blood pressure were minimal. We conclude that both 0.5% levobunolol and 0.5% timolol administered once daily are effective and safe in lowering IOP in most patients with ocular hypertension or open-angle glaucoma.

The value of indices in the central and peripheral visual fields for the detection of glaucoma

We assessed 81 patients in four groups (normal, low- and high-risk ocular hypertension, and early glaucoma) with the standard Octopus G1 central visual field program in addition to two quantitative programs, PFN (peripheral field-nasal) and PFT (peripheral field-temporal), designed for this study to test the nasal and temporal periphery, respectively. Indices were calculated for each program for each subject in all groups. We then examined the behavior of the indices across the separate visual field areas within each group as well as the behavior of the indices of each field area among the different groups. We found that quantitative testing of the peripheral nasal visual field provided valuable information in the detection of glaucomatous visual dysfunction additional to that provided by quantitative testing of the central visual field. Quantitative testing of the temporal periphery was less valuable.

RPC40, a unique gene for a subunit shared between yeast RNA polymerases A and C

Yeast RNA polymerases A and C share an approximately equal to 40 kd subunit. We have identified, sequenced, and mutagenized in vitro the AC40 subunit gene. The RPC40 gene is unique in the yeast genome and is required for cell viability. This gene contains an open reading frame encoding a 37.6 kd protein having no significant homology with bacterial RNA polymerase subunits. The promoter region contains a 19 bp sequence also present in the largest subunit of RNA polymerase C. It also contains a well-conserved RPG box, a sequence found in the promoter region of many genes encoding the translational apparatus. A novel, plasmid-shuffling method was developed to isolate a large number of RPC40 ts mutants. One of these, ts4, was shown to be defective in the synthesis of RNA polymerases A and C at the restrictive temperature. In contrast, RNA polymerase B was made normally.

Meiotic disjunction of circular minichromosomes in yeast does not require DNA homology

Circular plasmids containing an autonomously replicating sequence (ARS) and a centromeric DNA sequence (CEN) segregate as independent linkage groups during meiosis in Saccharomyces cerevisiae. If two genetically marked plasmids are present in the same diploid cell, their segregation during meiosis may be determined relative to each other. It has been observed that for centromere plasmids containing some DNA sequences in common, these plasmids tend to segregate away from each other at the first meiotic division [Clarke, L. & Carbon, J. (1980) Nature (London) 287, 504-509; Clarke, L., Fitzgerald-Hayes, M., Buhler, J.-M. & Carbon, J. (1981) Stadler Genet. Symp. 13, 9-23]. Here we show that nonhomologous plasmids, having no detectable DNA sequence cross-hybridization, also tend to disjoin from each other at the first meiotic division. Therefore, this nonrandom segregation to opposite poles can occur by mechanisms that do not involve DNA sequence homology. This process may be an active nonhomologous pairing system or it may reflect unknown physical restraints on the meiotic segregation of the two plasmids. In either case, this process cannot be used as a possible assay for homologous meiotic pairing.

Structure and sequence of the centromeric DNA of chromosome 4 in Saccharomyces cerevisiae

The CEN4 sequences from chromosome 4 that impart mitotic stability to autonomously replicating (ARS) plasmids in yeast cells have been localized to a 1,755-base-pair (bp) fragment. This fragment could be cut in half to give two adjacent, nonoverlapping fragments, that each contained some mitotic stabilization sequences. One of the half-fragments worked as efficiently as the larger fragment from which it was derived, while the other half provided a much poorer degree of mitotic stabilization. Sequencing of 2,095 bp of DNA including this region revealed the presence of a centromere consensus sequence, elements I, II, and III (M. Fitzgerald-Hayes, L. Clarke, and J. Carbon, Cell 29:235-244, 1982), in the half-fragment providing high levels of mitotic stability. The poorly stabilizing half-fragment did not contain any obvious sequence homologies to other centromere sequences. Deletion analysis of the 1,755-bp fragment indicated that removal of the 14-bp element I plus 16 of the 82 bp of element II impaired mitotic stability. Removal of elements I and II eliminated the mitotic stability provided by the consensus sequence.

Stimulation of ovine placental lactogen secretion by arachidonic acid

To determine whether arachidonic acid stimulates the secretion of ovine placental lactogen (oPL), arachidonic acid was infused as an intravenous bolus into pregnant ewes and fetuses. Plasma oPL concentrations were determined in mothers and fetuses before and for 5 h after infusion. The administration of 12.5 mg arachidonic acid (0.15-0.2 mg/kg, n = 11 experiments) to the pregnant ewes caused an increase in maternal plasma oPL concentrations of 73.9 +/- 15.6% (S.E.M.) and 60.8 +/- 18.1% above the pretreatment concentrations at 4 and 5 h respectively (P less than 0.01 in each instance). The infusion of 25 mg arachidonic acid (n = 8) caused increases of 96.0 +/- 19.1% and 100.3 +/- 26.4% (P less than 0.005), and the stimulation was not inhibited by the cyclo-oxygenase inhibitors indomethacin and ibuprofen. In contrast to arachidonic acid, vehicle alone or palmitic acid had no effects on plasma oPL concentrations. Despite the increase in maternal plasma oPL concentrations, plasma oPL concentrations in the fetus remained unchanged after the maternal infusions. The infusion of arachidonic acid (0.5-1.5 mg/kg) directly into six fetuses had no effects on either fetal or maternal oPL concentrations. These studies indicate that arachidonic acid stimulates maternal plasma oPL concentrations but has no effect on fetal oPL concentrations and the stimulation of oPL secretion is not due to the conversion of arachidonic acid to prostaglandins or other cyclo-oxygenase products.

Mitotic stability of yeast chromosomes: a colony color assay that measures nondisjunction and chromosome loss

A colony color assay that measures chromosome stability is described and is used to study several parameters affecting the mitotic maintenance of yeast chromosomes, including ARS function, CEN function, and chromosome size. A cloned ochre-suppressing form of a tRNA gene, SUP11, serves as a marker on natural and in vitro-constructed chromosomes. In diploid strains homozygous for an ochre mutation in ade2, cells carrying no copies of the SUP11 gene are red, those carrying one copy are pink, and those carrying two or more copies are white. Thus, the degree of red sectoring in colonies reflects the frequency of mitotic chromosome loss. The assay also distinguishes between chromosome loss (1:0 segregation) and nondisjunction (2:0 segregation). The most dramatic effect on improving mitotic stability is caused by increasing chromosome size. Circular chromosomes increase in stability through a size range up to approximately 100 kb, but do not continue to be stabilized above this value. However, linear chromosomes continue to increase in mitotic stability throughout the size range tested (up to 137 kb). It is possible that the mitotic stability of linear chromosomes is proportional to chromosome length, up to a plateau value that has not yet been reached in our synthetic constructions.

Deletion of plasmid sequences during Saccharomyces cerevisiae transformation

Saccharomyces cerevisiae was transformed with DNA by the lithium acetate method. Mutation of nonselected markers on the transforming vector was observed at a frequency several orders of magnitude higher than spontaneous mutation frequencies. These mutations were shown to be deletions. Linearization of the vector before transformation stimulated deletion formation.

Instability of dicentric plasmids in yeast

Dicentric plasmids containing either two copies of centromere 4 or one copy of centromere 4 and one copy of centromere 3 in the yeast plasmid vector YRp17 were constructed in vitro and introduced into yeast cells by DNA transformation. The resulting colonies were heterogeneous for a mixed population of rearranged plasmids. The rearrangements always involved deletion of one or both centromere sequences originally present on the plasmid. Heterogeneity was due to the continued production of deleted plasmids from a pool of unrearranged dicentric plasmids maintained within some of the yeast cells in the colony. The RAD52 gene product is known to be required for the repair of DNA double-strand breaks in yeast. Transformation of rad52 mutant yeast cells with dicentric plasmids gave rearranged plasmids similar to those observed with RAD+ yeast cells, but the transformation frequency was only 5-10% compared to transformation with monocentric plasmids. Also, the ratio of unrearranged dicentric plasmid to deleted plasmids was greatly reduced in the rad52-transformed cells. These observations are consistent with a model in which centromeric DNA sequences can interact independently with the yeast cell spindle apparatus. Occasional movement of centromeres to opposite poles may result in mechanical breakage of plasmid sequences. Plasmids deleted for one or both centromere sequences can be obtained from these broken molecules and are resistant to further rearrangement.

Reversion of a promoter deletion in yeast

Promoter function in yeast has been examined by obtaining revertants of a his3 promoter deletion in vivo. Events which provide a new promoter for the his3 gene include insertion of the transposable element Ty1, rearrangements of the plasmid vector, and chromosomal mutations. A role for dicentric chromosomes as a source of the plasmid rearrangements is discussed.