[Studies on the early serodiagnosis of leptospirosis by dot-ELISA]

Thirty serum samples of patients with early leptospirosis from whom cultures of leptospira were positive were tested by dot-enzyme linked immunosorbent assay (dot-ELISA) and microscopical agglutination test (MAT). The results showed that the positive rate of dot-ELISA (40%) was higher than that of MAT (13.3%). One-hundred and ninety-eight serum samples from patients with clinical diagnosis of early leptospirosis were tested by dot-ELISA, MAT and blood culture. The results showed that the positive rate of dot-ELISA (64.6%) was higher than that of blood culture (15.2%) and MAT (14.1%). The longer the time of the illness, the lower the positive rate of the blood culture. However, the positive rate of dot-ELISA was stable in different stages of the illness.

UNDULATORY SWIMMING: HOW TRAVELING WAVES ARE PRODUCED AND MODULATED IN SUNFISH (LEPOMIS GIBBOSUS)

We have developed an experimental procedure in which the in situ locomotor muscles of dead fishes can be electrically stimulated to generate swimming motions. This procedure gives the experimenter control of muscle activation and the mechanical properties of the body. Using pumpkinseed sunfish, Lepomis gibbosus, we investigated the mechanics of undulatory swimming by comparing the swimming kinematics of live sunfish with the kinematics of dead sunfish made to swim using electrical stimulation. In electrically stimulated sunfish, undulatory waves can be produced by alternating left­right contractions of either all the axial muscle or just the precaudal axial muscle. As judged by changes in swimming speed, most of the locomotor power is generated precaudally and transmitted to the caudal fin by way of the skin and axial skeleton. The form of the traveling undulatory wave ­ as measured by tail-beat amplitude, propulsive wavelength and maximal caudal curvature ­ can be modulated by experimental control of the body's passive stiffness, which is a property of the skin, connective tissue and axial skeleton.

Physical properties and quantification of the ECT stimulus: I. Basic principles

The physical properties of the electroconvulsive therapy (ECT) stimulus markedly affect both efficacy and side effects. We review basic principles in characterizing these physical properties and in quantifying the ECT stimulus. The topics discussed include the application of Ohm's law, alternative composite units of ECT dosage (energy and charge), the use of constant-current, constant-voltage, and constant-energy principles in ECT devices, the nature of current shunting in ECT and the determinants of impedance, the relations between impedance and seizure threshold, the seizure-eliciting efficiency of alternative stimulus waveforms and of stimulus parameter configurations, and the role of reactive components (capacitance and inductance) in the ECT circuit. New findings are also presented regarding several of these issues.

Cerebellar infarction. Analysis of 22 cases

Twenty-two cases of cerebellar infarction were diagnosed by clinical findings, computerized tomography (CT), magnetic resonance image (MRI) and autopsy. Most of the infarctions occurred in the territory of the posterior inferior cerebellar artery (18/22). The most common and earliest symptoms were dizziness or vertigo (19/22), which occurred repeatedly and were accompanied by nausea and vomiting. The symptoms and signs of cerebellar lesion such as unsteady gait, limb and/or trunk ataxia, dysarthria were also the main clinical manifestations. However, in a number of patients there were no cerebellar symptoms or signs (9/22). Rapid deterioration of consciousness suggested acute compression of the brainstem, where the prognosis would be poor. CT scan made it possible to diagnose cerebellar infarction in the patients. But CT is not a satisfactory instrument in identifying this disease. MRI without bony artifacts from the posterior fossa has much higher resolution and renders the infarction to be visualized earlier. It may be regarded as the most ideal instrument in diagnosing this disease.

[Cross transposition of expanded scalp flaps for the treatment of postburn cicatricial alopecia]

When the area of alopecia is very large, the normal scalp is not sufficient to cover the defect resulting from excision of the alopecia. From August 1987 to December 1989, 8 cases with large defect of scalp are repaired by means of expanded cross scalp flaps with good result. Among 8 cases, 7 are male and 1 female, and the largest area of alopecia is 300 cm2 and the smallest 112 cm2, with a mean of 191 cm2. Two expanders are buried under the galea aponeurotica on both sides of alopecia, and the scalp is expanded. The central part of the expanded scalp is chosen to form the "major flap", the lateral part of the expanded scalp to form the "adjuvant flap". Two flaps are then crossed and the defect is repaired. The method of scalp expansion and "axial flap" is used in marginal alopecia. An expander is buried under the galea aponeurotica on each side of the alopecia. After the scalp is expanded, the central part of the expanded scalp is chosen to from "axial flap" with the pedicle consisting of superficial temporal artery or occipital artery and the lateral part of the expanded scalp to form the "adjuvant flap". Then two flaps are transposed and the defect is thus repaired.

Costs associated with office visits for diarrhea in infants and toddlers

We determined costs associated with diarrhea in a < 36-month-old ambulatory population. Children with acute diarrhea were enrolled during the rotavirus season at three centers. Questionnaires to assess costs of both medical and nonmedical factors were administered at the enrollment visit and 1 week later. Office computer records were reviewed to identify all visits by children with diarrhea during 1 year. Fifty-one patients were enrolled. The average cost per episode of diarrhea was $289, which included: $144, missed work; $57, office visits; $23, laboratory tests; $21, medications; $18, changed diet/oral rehydration solutions; $15, travel; $7, extra diapers; and $6, extra child care. During 1 year diarrhea accounted for 4% of all visits and 10% of visits among those < 36 months old. The annual cost at the three centers was $346,000, which extrapolates to $0.6 to $1.0 billion for the United States. Twenty-one percent of this cost was attributable to rotavirus diarrhea. We conclude that outpatient care for pediatric diarrhea is a major health care cost in the United States.

Lesions of the hippocampus enhance or depress humoral immunity in rats

The effect on the humoral immune response in rats by bilaterally destroying cell bodies in the hippocampus with kainic acid or by electrolytic lesion was studied. After 3 days a humoral immune response was evoked by injecting 1 ml of 10% sheep red blood cells. Five days later, the haemolysin content (MC50) was measured. Chemical destruction of pyramidal cell bodies in CA2 and CA3 significantly increased humoral immunity as measured by HC50, but larger chemical lesions that also included CA1 did not. Electrical destruction of cell bodies and axonal pathways in CA2 and CA3 did not significantly affect HC50. These results suggest that different areas of the hippocampus can stimulate or inhibit humoral immunity.

Shade selection and laboratory communication

This article reviews some of the factors involved in shade selection for prosthetic teeth and suggests simple techniques for accurately transmitting information about the desired color to the laboratory technician.

Three-dimensional structure of tyrosine phenol-lyase

Tyrosine phenol-lyase (EC 4.1.99.2) from Citrobacter freundii has been cloned and the primary sequence deduced from the DNA sequence. From the BrCN digest of the NaBH4-reduced holoenzyme, five peptides were purified and sequenced. The amino acid sequences of the peptides agreed with the corresponding parts of the tyrosine phenol-lyase sequence obtained from the gene structure. K257 is the pyridoxal 5'-phosphate binding residue. Assisted by the sequence data, the crystal structure of apotyrosine phenol-lyase, a pyridoxal 5'-phosphate-dependent enzyme, has been refined to an R-factor of 16.2% at 2.3-A resolution using synchrotron radiation diffraction data. The tetrameric molecule has 222 symmetry, with one of the axes coincident with the crystallographic 2-fold symmetry axis of the crystal which belongs to the space group P2(1)2(1)2 with a = 76.0 A, b = 138.3 A, and c = 93.5 A. Each subunit comprises 14 alpha-helices and 16 beta-strands, which fold into a small and a large domain. The coenzyme-binding lysine residue is located at the interface between the large and small domains of one subunit and the large domain of a crystallographically related subunit. The fold of the large, pyridoxal 5'-phosphate binding domain and the location of the active site are similar to that found in aminotransferases. Most of the residues which participate in binding of pyridoxal 5'-phosphate in aminotransferases are conserved in the structure of tyrosine phenol-lyase. Two dimers of tyrosine phenol-lyase, each of which has a domain architecture similar to that found in aspartate aminotransferases, are bound together through a hydrophobic cluster in the center of the molecule and intertwined N-terminal arms.

DRD2 dopamine receptor genotype, linkage disequilibrium, and alcoholism in American Indians and other populations

We defined interpopulation differences in the frequency of the dopamine D2 receptor DRD2/Taq1 A1 allele, which has previously been associated with alcoholism. Frequencies of the A1 allele in unrelated subjects were 0.18 to 0.20 (se = 0.02 to 0.03) in several Caucasian populations previously assessed, 0.38 (+/- 0.05) in American Blacks (n = 44), 0.63 (+/- 0.07) in Jemez Pueblo Indians (n = 23), and 0.80 (+/- 0.04) in Cheyenne Indians (n = 52). The existence of large interpopulation differences in the frequency of the Taq1 alleles suggests that associations to disease status could readily be generated or masked if disease and control groups were uneven in ethnic composition. To address the possibility that the 4-fold higher frequency of the A1 allele in Cheyenne Indians was related to an increased vulnerability to alcoholism in that population, 47 Cheyenne Indians were psychiatrically interviewed and blind-rated. However, there was no significant difference between interviewed controls (0.73 +/- 0.06, n = 24), subjects with alcoholism and/or drug abuse (0.74 +/- 0.06, n = 23) and noninterviewed population controls (0.87 +/- 0.05, n = 20). Legitimate association of the DRD2/Taq1 allele to alcoholism would presumably require it to be in linkage disequilibrium (nonrandom association) with a functional mutation at DRD2 or elsewhere. The level of disequilibrium would vary between populations and could place an upper bound on the strength of an association.(ABSTRACT TRUNCATED AT 250 WORDS)

The significance of choroid plexus cysts in fetuses at 18-20 weeks. An indication for amniocentesis?

Over a period of 25 months, all antenatal patients were offered a detailed ultrasound scan at 18-20 weeks' gestation. The lateral cerebral ventricles were scanned for the presence of choroid plexus cysts. Fifty-one patients found to have choroid plexus cysts were offered amniocentesis to exclude chromosomal abnormalities. One pregnancy, in which the only abnormality found was bilateral choroid plexus cysts, was terminated after trisomy 18 was detected on amniocentesis at 19 weeks. The other 50 pregnancies had normal fetal outcomes. The significance of the isolated finding of choroid plexus cysts is reviewed.

Comparison of the fracture strengths of ceramometal crowns versus several all-ceramic crowns

Fracture resistance to forces applied to the incisal edges of four types of anterior crowns was tested. Ceramometal crowns fractured at significantly higher values (720 psi) than the all-ceramic crowns (approximately 360 psi). No significant difference was found among the fracture values of the Dicor crowns, the aluminous porcelain jackets, and the crowns fabricated from Dicor veneered with aluminous body and incisal porcelain.

Applications and limitations of vitreoretinal biopsy techniques in intraocular large cell lymphoma

The cases of 4 patients with clinical signs of intraocular large cell lymphoma are described. Initial cytopathologic examination of vitrectomy specimens failed to establish the malignant character of the vitreous infiltrates. Three of the four patients eventually developed solid central nervous system tumors, intracranial biopsy samples of which revealed large cell lymphoma, 13 months to 42 months after initial examination. In one patient, transscleral retinochoroidal biopsy confirmed the diagnosis at the same time as negative vitreous cytologic examination. Results of cytopathologic examination alone of vitreous biopsy specimens may not be sufficient to make a diagnosis in certain cases of large cell lymphoma that are subsequently documented by CNS biopsy. Careful attention should be paid to the handling, processing, and interpretation of vitrectomy specimens from patients suspected of having intraocular large cell lymphoma. Consideration should be given to immunocytologic staining and interpretation by centers that are highly experienced in vitreous cytopathology.

[Cerebellar infarction and its assistant examination]

The clinical manifestations of cerebellar infarction are often non-particular and it is difficult to make such a diagnosis clinically. Diagnosis was based on pathology previously. Most of the cases were overlooked while still living and the true morbidity was not known. CT scan has made the diagnosis of this disease possible clinically in some patients, but CT is still not an ideal instrument for diagnosing this disease because of the interference by bony artifacts of posterior fossa. The advent of MRI made it possible to distinguish cerebellar infarction safely and easily. It is not the most powerful tool for diagnosing this disease. The authors reported 15 cases of cerebellar infarction diagnosed by clinical manifestation, neuroimages and pathology and pointed out that further knowledge of this disease is needed.

[Non-operation management of 12 cases with brain abscess demonstrated by CT scan]

This paper reported 12 cases with brain abscess demonstrated by CT scan. Using antibiotic management without surgical intervention, in 10 cases the curative effects were satisfactory. The paper indicated that CT scan was very useful in prompt and correct diagnosis of brain abscess and with sequential CT scan medical therapy was feasible. It is significant in treatment of brain abscess especially for the patients who have a poor general condition, have the brain abscess located in important functional area or have multiple abscesses so that the operation is difficult for them.

What about the carers? The need for staff support in healthcare

Burnout in the health service is costing us dear. Not only are desperately needed staff leaving the service, but evidence suggests it means patients take longer to recover. What effect can staff support have on the problem?

Some requirements and suggestions for a methodology to develop knowledge based systems

This paper describes an approach to the creation of a methodology for the development of knowledge based systems. It specifies some requirements and suggests how these requirements might be met. General requirements can be satisfied using a systems approach. More specific ones can be met by viewing an organization as a network of consultations for coordinating expertise. The nature of consultations is described and the form of a possible cognitive model using a blackboard architecture is outlined. The value of the approach is illustrated in terms of certain knowledge elicitation methods.

Splenosis masquerading as small bowel neoplasm

Incidental discovery of a mass during laparoscopic surgery resulted in exploratory laparotomy for a young woman. The mass' uncharacteristic appearance belied its true identity as displaced splenic tissue. The authors suggest ways to identify splenosis without resorting to further surgery.

Conjugation of monoclonal antibodies to a synthetic peptide substrate for protein kinase: a method for labelling antibodies with 32P

In recent years, radiolabelled monoclonal antibodies have been evaluated for their use in the diagnosis and treatment of neoplastic disease. One isotope which has not been assessed for antibody targeting is 32P, even though it has many favourable radiobiological characteristics and has been used clinically for the treatment of certain neoplastic disorders such as polycythaemia rubra vera. The main drawback so far in using 32P has been the absence of a general method for phosphorylating antibodies. We have now developed a novel process for the phosphorylation of immunoglobulins which is rapid, efficient and allows high specific activities to be achieved (greater than 10 muCi micrograms-1). The technique involves the chemical conjugation of Kemptide, a synthetic heptapeptide substrate for kinases, to immunoglobulins. The antibody-Kemptide conjugate can then be phosphorylated using protein kinases and [32P]-gamma-ATP. The procedure does not compromise the binding activity of the antibody. The 32P-labelled monoclonal antibodies were stable in human, mouse and rat plasmas in vitro, although they cleared from the bloodstream of mice with a beta-phase half life of 2 days which is approximately two times faster than that of native antibody. The application of this phosphorylation technique should allow the therapeutic potential of targeted 32P to be assessed.

Why families change pediatricians. Factors causing dissatisfaction with pediatric care

Dissatisfaction with their child's physician sometimes causes parents to transfer to a new provider. We studied the reasons for such transfers from four pediatric practices in Chittenden County, Vermont. Personal qualities of the physician, including the parent's perception of the physician's communication skills, his or her clinical competence, and the apparent level of concern were the most important factors that distinguished satisfied from dissatisfied parents. Structural features, including costs, waiting time, and continuity with the same physician, were less often sources of enough dissatisfaction to produce a transfer. Effectiveness and success in pediatric practice are dependent on competence, communication, and caring.

Cytoxicity of erythrocyte ghosts loaded with ribosome-inactivating proteins following fusion with CHO cells

The ribosome-inactivating proteins gelonin, Momordica charantia inhibitor, pokeweed antiviral protein, and one from Saponaria officinalis were enclosed in human erythrocyte ghosts. The proteins once trapped in ghosts and fused with CHO cells inhibited colony formation at concentrations of approximately 1 ng/ml (3 X 10(-11) M), whereas the free proteins only had an effect at concentrations of greater than 1 microgram/ml.

"Serious drinking," "white man's drinking" and "teetotaling": drinking levels and styles in an urban American Indian population

The differences between abstainers, moderate drinkers and heavy drinkers were examined in American Indians living in Los Angeles, California. Equal numbers of these three groups (total N = 155) were selected from four tribal groups: Siouan-speaking, Navaho, Five Civilized Tribes (of eastern Oklahoma origin) and indigenous California tribes. The relative predictive powers of sociostructural, cultural and psychological variables in accounting for current drinking levels were then assessed. The results indicated that, much as for non-Indian populations, heavy drinkers were more likely to have had heavy-drinking models in the family of origin, to be men and to score high on psychophysiological stress indices. Socioeconomic status and traditionalism were found to be weaker predictors of drinking level. Differences in drinking styles over individuals' lifetimes and between tribes were also studied. Ethnographic observations, case vignettes and statistical summaries of the sample by tribe and by drinking level showed that tribal origins, age and socioeconomic status influenced drinking style and attitudes toward alcohol, even if they did not predict the current drinking level of the subjects.

The effect of antisecretagogues on gastric microflora

We examined the effect of cimetidine in altering gastric microflora in patients undergoing gastric resection for peptic ulcer disease. Ten patients had administration of cimetidine stopped at least six hours before surgery. Their mean gastric pH was 2.02 +/- 1.51, and 0.4 +/- 0.97 organisms were isolated per patient. Ten patients were maintained on a regimen of cimetidine and their mean gastric pH was 5.69 +/- 1.80, with 3.2 +/- 1.62 organisms isolated per patient. We reached the following conclusions: cimetidine alters the gastric pH of preoperative patients; cimetidine therapy is associated with an increase in gastric flora; stopping administration of cimetidine six hours before surgery reacidifies the stomach, decreases the number of organisms isolated from the stomach, and decreases the risk of septic complications.

Effect of healing on small internal diameter arterial graft compliance

Porosity is an essential component for long term function of small internal diameter synthetic vascular prostheses. Theoretically, porosity is required for healing by providing a scaffold for ingrowth of periprosthetic tissues. Porosity may be required for transfer of fluids and ions in prostheses even if tissue ingrowth does not occur. Increased permeability of vascular grafts has been shown to enhance tissue incorporation. Implants with pore sizes greater than 10 microns but less than 45 microns become ingrown with fibrohistiocytic tissue and capillaries. Implants with pore sizes greater than 45 microns are ingrown with organized fibrous tissue and minimal histiocytic response. The phenomenon of differential ingrowth may have important functional significance. Prostheses which heal with organized fibrous tissue have the potential for long term contracture, strangulation of vascularity and calcification. Fibrohistiocytic tissue has low mechanical strength and does not appear to contract or calcify. Elastomeric microporous vascular prostheses which are minimally ingrown or ingrown with fibrohistiocytic tissue maintain compliance after months of implantation. This study was designated to determine the effects of healing on the compliance of small internal diameter vascular replacements and to correlate the compliance to patency rates.

Thrombogenicity and the interaction of proteins, platelets and white cells

Radioactive labeled protein and platelet studies suggest that an ideal vascular surface absorbs albumin and prevents platelet adherence and aggregation. This study examines the interaction of serum and plasma proteins, white cells, and platelets in the thrombotic response to small internal diameter vascular prostheses. Thirty-seven replamineform silicone rubber vascular prostheses, 4 mm internal diameter and 6 cm length, had 5% aspirin and 5% theophylline by weight dispersed in a luminal coating (D); the remaining 37 control (C) prostheses had an identical silicone rubber coating without drugs. Scanning electron and darkfield microscopy confirmed similar surface topography in C and D grafts. One C and one D graft were studied in parallel using a modified canine arteriovenous fistula. Consistently, D prosthesis had increased bleeding through the graft wall. The 7 serum and 8 plasma experiments demonstrated greater accumulation on the D prostheses, the greatest deposition occurring within the first 30 minutes. In 8 platelet experiments, D grafts accumulated more radioactivity at both the 5 and 30 minute intervals. Six mononuclear and 8 PMN experiments had less accumulation on the D grafts at 15 minutes and no consistent difference at 60 minutes. Elution of C and D Grafts demonstrated significant drug levels in only the D grafts at the beginning of the experiments and after 15 minutes of exposure of blood. We conclude: (1) aspirin and theophylline have an effect on the initial interaction of plasma proteins, platelets and white cells in the thrombogenic response, (2) the effect diminishes as time released drug levels decrease.

Noninvasive evaluation of peripheral vascular disease using transcutaneous oxygen tension

Transcutaneous oxygen tension (PtcO2) was used for noninvasive determination of blood supply in 25 patients evaluated for peripheral arterial disease. PtcO2 values were compared with segmental Doppler pressure, pulse volume recording, pulse reappearance time, and angiography in patients being evaluated for wound healing problems, amputations, and peripheral bypass procedures. PtcO2 was measured using a heated (45 degrees C) Clark polarographic electrode to quantitate the oxygen which diffuses from the dermal capillaries to the skin surface. Control PtcO2 values recorded over the chest or shoulder taken while patients were breathing room air were 78 +/- 8 mm Hg. PtcO2 values greater than 50 mm Hg predicted success for levels of amputation and for wound healing without reconstructive procedures; values of 40 mm Hg or less were associated with continued wound problems and complication after amputation. Increased PtcO2 values after vascular reconstruction of the legs predicted improved clinical status on follow-up examinations up to 6 months. PtcO2 predicted the extent of vascular disease as well as the other noninvasive tests and angiography. We conclude that (1) PtcO2 tension is a simple, accurate, noninvasive method to determine the appropriate level of amputation, wound healing potential, and effectiveness of bypass procedures, and (2) PtcO2 values correlate well with angiography and noninvasive evaluations.

A new pressure measuring system for cushins and beds--with a review of the literature

An interface pressure measuring device for the assessment of subject-cushion interface pressures at ten points has been described. Preliminary trials using 12 healthy subjects on four cushions and three spinal injury patients on six cushings, has been carried out. It was also found that the water and foam cushion distributed the pressure over a large area than the foam cushions.

Division of attention between simultaneous and successive nonverbal signals varying in discriminability

Impaired performance indexed by accuracy usually accompanies the division of attention between simultaneous difficult signals. Presenting the signals successively reduces the impairment. Presenting easy signals eliminates it. Both variables crucial to these findings, relative time of onset and discriminability, were manipulated in the first experiment using a two-choice recognition paradigm involving bimodal signals. The results showed that, when a difficult signal was followed by two simultaneous easy ones, in a different modality from the first, performance was significantly worse on each than on the same signals presented alone. Simultaneous presentation of all three signals further increased the impairment for the difficult signal, but not for the easy ones. In the second experiment, the discriminability of the following signals was varied. The results showed, that when a difficult signal was followed by either two simultaneous easy signals, in a different modality from the first, or by two difficult ones, performance was significantly worse than on the same difficult signal presented alone. Further, when the preceding difficult signal was auditory, but not when it was visual, performance was better with easy following signals than with difficult ones. It is argued that an adequate account of the results from the two experiments requires the following assumptions concerning the processing of multiple signals: (1) a loss associated both with the acquisition and the storage of information, (2) preferential processing of visual signals over auditory ones. Proposals are made for the incorporation of both assumptions into a single model of divided attention.

Division of attention: evidence for a between-trial component of impaired performance

Detection and recognition studies are reviewed, which show a dependency between errors on successive trials. They suggest the impairment accompanying the presentation of simultaneous signals may also involve a similar “between-trial” component. The hypothesis was tested using a two-choice recognition paradigm with bimodal signals. Dimensions presented simultaneously were interleaved on alternate trials with a single dimension presented alone. Interleaving two signals in the first experiment showed no effect on the following signal presented alone, compared to a control condition in which the signal always preceded itself. Interleaving four signals in the second experiment produced a significant impairment. Accounts of the results based on the length of the response interval, fluctuations of state variables such as arousal and decay of the memory trace are rejected. Accounts based on the impairment and set-size of preceding simultaneous signals are retained. Both suppose part of the impairment accompanying simultaneous signals to be a between-trial phenomenon. Implications of the results for work on divided-attention are considered and a method of experimental control proposed.