Telemedicine in Latin America

Latin America, stretching 6,000 miles from Mexico to Tierro del Fuego, is comprised of twenty countries totaling nearly 1/2 billion people. There are wide variations in median income levels, medical access, telecommunications infrastructures, and levels of rurality. The great variety of settings precludes any simple approach to telemedicine deployment.

Home health visits using a cable television network: user satisfaction

There are about 1.5 million home patients who receive home health care (nurses visiting patients in their homes) in the US each year. In a significant proportion of these visits, hands-on care is not needed. Rather, the nurse needs to verify compliance with medication regimes, assess mental or emotional status, or check blood sugar levels, blood pressure and the like. Many of these activities might be handled by a nursing visit using interactive video to the patient's home, saving the nurse's time wasted in driving, finding parking, etc. A system for delivering home health care using interactive video has been piloted in the state of Kansas. Using the local cable television infrastructure for audio and video transmission, this system permits a nurse to see patients in their homes for a fraction of the cost of an on-site visit. This new method of delivering home health care is being evaluated with an ongoing study of utilization and user satisfaction. We conducted a prospective survey administered to home health nurses (n = 2) and homebound patients (n = 3) using a cable TV-mediated interactive video system, to assess utilization and user satisfaction with televideo-mediated home health care visits. One hundred and eighty-one patient questionnaires and 193 nurses questionnaires were completed. The average length of a visit was 15 minutes (range 1-91). All mean scores tabulated for the questions indicated strong nurse and patient satisfaction with the system. Participating nurses and clients were satisfied with the televideo encounters. The mean score for all questions was better than neutral. Recognizing that this was a pilot study, hampered by small numbers and subject to the inherent biases of a single institution study, the results support further investigation and implementation of this modality for home health care.

A pilot study of the physician acceptance of tele-oncology

During the winter of 1993, medical oncologists from an urban, university-based hospital provided oncology care to rural patients using interactive video clinics (tele-oncology). In order to assess physician satisfaction with this form of outreach, surveys were performed after the video encounters, as well as after a limited number of subsequent clinical encounters on site. Various aspects of satisfaction were evaluated. Although the sample was small (a total of 41 clinical encounters and 3 oncologists), the results suggested that there was a reasonable level of physician satisfaction with, and confidence in, the use of video to replace some on-site oncology consultations. A definitive study of tele-oncology for providing care to rural cancer patients therefore appears to be warranted.

Relationship between gastric mucus synthesis, secretion and surface gel erosion measured in amphibian stomach in vitro

1. The layer of adherent mucus that protects the surface of the stomach reflects a dynamic balance between biosynthesis of glycoprotein, secretion of preformed mucus and erosion of the adherent gel layer. The present study is the first in which all these processes have been measured concomitantly and was undertaken to define interrelationships between the three parameters. 2. A chambered sac preparation of amphibian gastric mucosa is described. Biosynthesis was determined by specific incorporation of radiolabelled sugars into purified glycoprotein. Mucus secretion was determined by measuring the thickness of the adherent gel and erosion of the surface layer was assessed from the appearance of soluble mucin in the luminal solution. 3. 16,16-Dimethyl-prostaglandin (PG) E2 stimulated glucosamine incorporation by 10-fold, but did not alter the rate of incorporation of galactose. There was a rapid two-fold increase in the thickness of the adherent mucus layer but no change in the rate of erosion. Dibutyryl-cAMP also stimulated mucus release but, unlike PG, increased glycoprotein labelling by galactose. 4. Both distention or the application of a cholinergic agonist increased adherent mucus thickness. Stimulation of mucus release in response to carbachol was accompanied by a decrease in glycoprotein labelling by galactose. In contrast, the adrenergic agent noradrenaline decreased secretion but did not influence labelling. 5. These results indicate that biosynthesis and secretion of gastric mucus are subject to differential regulation. Moreover, the profile of incorporation of sugars in response to secretagogues also differs, indicating the need for caution when interpreting effects on glycoprotein biosynthesis.

Mucus and H. pylori

A continuous, adherent mucus gel layer with mucosal bicarbonate secretion is the initial protective barrier in the stomach and duodenum against erosion by the gastric juice. H. pylori resides within the adherent mucus gel layer close to the epithelial surface. The barrier function of the mucus layer in vivo depends on (i) its thickness, and (ii) its gel structure, a property which is linearly dependent on the polymeric mucin content. We have shown in vivo that H. pylori colonisation alone did not decrease the thickness of the adherent gastric mucus barrier, although there was a mean 20% decrease in mucus thickness in those H. pylori positive subjects with underlying gastric atrophy. There was, however, a significant mean 18% reduction in the gel-forming polymeric mucin content of mucus from H. pylori subjects, independent of underlying atrophy. Studies in vitro suggest this loss of gel structure might arise from a H. pylori mediated, high local pH generated by urease activity rather than by proteolysis. This study shows that H. pylori infection alone does not compromise the overall integrity of the mucus barrier in vivo. However, in the immediate environment of the organism there appears to be a localised loss of mucus gel structure. The mucus barrier is compromised if H. pylori associated gastric atrophy or peptic ulceration follows.

Association of genetic variations in apolipoprotein B with hypercholesterolemia, coronary artery disease, and receptor binding of low density lipoproteins

To search for unique mutations in the apolipoprotein B (apoB) gene that disrupt the binding of LDL to its receptor and cause hypercholesterolemia, we examined more than 800 patients with high LDL cholesterol levels and/or coronary artery disease (CAD). Analysis of patient DNA by single-strand conformation polymorphism and allele-specific oligonucleotide hybridization of the sequence surrounding the putative receptor- binding domain of apoB (amino acid positions 2965 to 3534) revealed seven variations. LDL from heterozygotes with either Arg 3500 Gln or Arg 3531 Cys bound defectively with the LDL receptor in competitive binding assays. The Arg 3500 Gln substitution was statistically more prevalent in patients with hypercholesterolemia (P = 0.0003). Total cholesterol and LDL-cholesterol were significantly higher (P< 0.0004) in 34 apoB 3500 Gln carriers than in the controls. The allele encoding the Arg 3531 Cys substitution was more prevalent (0.8%) in the CAD group (P = 0.05) than in the controls. A Ser 3252 Gly variant was statistically more prevalent in the hypercholesterolemic group (P = 0.03), but LDL with this mutation had normal LDL receptor-binding activity. The other four variants identified (Leu 3350 Leu, Gln 3405 Glu, Val 3396 Met, and Ser 3455 Arg) were not associated with defective LDL-receptor binding, hypercholesterolemia, or CAD, nor were the apoB mutations associated with elevated lipid levels in family members. The surprising result that only two mutations of apoB in the receptor-binding domain (Arg 3500 Gln and Arg 3531 Cys) were associated with defective LDL binding, hypercholesterolemia, or CAD is in stark contrast with familial hypercholesterolemia, where nearly 150 mutations of the LDL receptor have been described that disrupt its function. This study strongly suggests that a limited number of mutations of apoB markedly influence LDL binding to its receptor.

Effect of nicotine on large bowel mucus thickness, eicosanoids and faecal proteinase in ferrets

BACKGROUND

Following observations on the effect of subcutaneous nicotine on rectal mucosal eicosanoids and mucus in the rabbit we have repeated the work in ferrets which may be a more suitable animal model.

AIMS AND METHODS

The effect of nicotine on mucosal eicosanoids, the adherent mucus layer, and faecal proteinases in the large bowel of ferrets was examined in forty animals randomly allocated to five groups, a control and four treatment groups. They were given subcutaneous saline or nicotine via an Alzet pump in doses of 0.3, 0.6, 1.2 and 2.0 mg/kg/day for 10 days and then sacrificed; measurements were made of serum nicotine and cotinine levels, rectal mucosal eicosanoids, adherent rectal and colonic mucus thickness, and faecal proteinases.

RESULTS

No significant differences were observed for any measurements, except for serum nicotine and cotinine levels, which were raised consistent with the dose given.

CONCLUSION

Nicotine had no effect on measurements, which may possibly be important in the relationship between smoking and ulcerative colitis.

Prospective, randomized, double-blind study of high-dose aprotinin in pediatric cardiac operations

BACKGROUND

Perioperative aprotinin decreases postoperative blood loss in adults undergoing cardiac operations, but its role is less clear in children. Therefore, a trial of aprotinin in pediatric cardiac operations was conducted to study the efficacy of its use in children.

METHODS

Forty-two patients were randomly assigned to receive either high-dose aprotinin or placebo. Aprotinin efficacy was assessed using time from protamine administration to skin closure, postoperative blood loss and hemoglobin loss, and postoperative transfusion requirements. Measures of fibrinolysis (fibrin degradation product titers) and platelet preservation (beta-thromboglobulin levels) were also assessed.

RESULTS

There were no statistically significant differences between groups in any of the blood loss or transfusion parameters. Fibrin degradation product levels, measured 4 hours postoperatively, had increased significantly for control patients, but remained unchanged for the aprotinin group (p < 0.02). beta-Thromboglobulin levels increased more rapidly during cardiopulmonary bypass in the control group (p = 0.03).

CONCLUSIONS

Aprotinin appears to provide no clinical benefit in routine pediatric cardiac operations. A reduction in fibrinolysis, with perhaps an early preservation of platelet structure, is seen in the aprotinin group.

Practising oncology via telemedicine

Although there are increasing numbers of telemedicine programmes in the USA, few have offered teleoncology services, so that the role of telemedicine in the practice of clinical oncology has yet to be fully defined. Telemedicine has been used successfully for direct patient care in Kansas. It is also a method of providing supportive care for the cancer patient, including assessments of pain and nutrition. In addition, televised tumour conferences and nursing education courses can help smaller communities develop a level of expertise that allows patients to be treated locally. Telemedicine may well be used in future for access to national and international cancer experts, and for participation in new cancer treatment protocols through cooperative group trials. When practising oncology via telemedicine, there are unique problems, including issues regarding technology (interactive video and radiograph review) and practice (patient/oncologist preferences and doctor-patient communication). Very little has been published in the area of tele-oncology so far, and studies concerning its efficacy, cost-effectiveness and the best organizational structure are still in progress. However, telemedicine appears to be a useful technique in the practice of oncology.

A polydisperse linear random coil model for the quaternary structure of pig colonic mucin

The distribution of molecular weights for polymeric colonic mucus glycoprotein or "mucin" isolated and solubilised in the presence of protease inhibitors from pig colons is shown to be considerably greater than its "subunit" (thiol reduction product) and papain digested forms using the technique of size-exclusion chromatography coupled to multi-angle laser light scattering, and confirmed by sedimentation equilibrium measurements. The conformation of this mucin is probed by examining the molecular weight-intrinsic viscosity relationship in terms of the Mark-Houwink-Kuhn-Sakurada analysis for its polymeric (or "whole"), reduced and papain-digested forms: an exponent "a" of (1.1 +/- 0.1) is obtained indicating a linear random coil conformation consistent with other mucins. Size-exclusion chromatography coupled to multi-angle laser light scattering is shown to provide a relatively simple complementary technique to sedimentation equilibrium for the molecular weight distribution analysis of polydisperse materials.