Case-based learning of plans and goal states in medical diagnosis

We introduce a case-based system, BOLERO, that learns both plans and goal states. The major aim is that of improving the performance of a rule-based diagnosis system by adapting its behavior using the most recent information available about a patient. On the one hand BOLERO gets knowledge from cases in the form of diagnostic plans that are represented as sequences of decision steps. The advantages of this representation include: (1) retrieval and adaptation of parts of plans (steps) appropriate to the current problem state; (2) generation of new plans not previously available in memory; and (3) learning from experience, both from successful or failed plans. On the other hand, since goal states are sets of final diagnosis likelihoods they are not known beforehand, i.e. goal states are not defined and the system has to learn to recognize them. For this reason BOLERO has a case-based method that uses solutions of past cases to recognize a diagnostic state as a goal state of a new planning problem. BOLERO and a rule-based system are integrated into a meta-level architecture in which we emphasize the collaboration of both systems in solving problems. The rule-based system executes the plans generated by BOLERO. As a consequence of the execution of plans, the rule-based system furnishes BOLERO with new information with which BOLERO can generate a new plan to adapt the reasoning process of the rule-based system into correspondence with the recent available data. All the methods have been designed to be useful for medical diagnosis and have been tested in the domain of diagnosing pneumonia.

Febrile ulceronecrotic Mucha-Habermann disease: a case report and review of the literature

A 32-year-old male with febrile ulceronecrotic Mucha-Habermann disease (FUMHD) responsive to methotrexate is reported. This is a severe variant of pityriasis lichenoides et varioliformis acuta characterized by the acute onset of a widespread ulceronecrotic cutaneous eruption together with high fever and systemic involvement. To our knowledge, only 13 patients with FUMHD have been reported to date.

Lactose maldigestion and milk intolerance: a study in rural and urban Mexico using physiological doses of milk

Lactose digestion capacity after ingestion of physiological doses of milk and its effect on milk intolerance and consumption were studied in rural and urban populations from three regions of Mexico with different milk intakes. All subjects (n = 926) received two treatments: whole milk (240 mL for children and 360 mL for adults) and the same amount of 90% lactose-hydrolyzed milk; 72% of the subjects also received as a third treatment a water solution containing lactulose (8 g for children and 10 g for adults). Lactose maldigestion determined by a hydrogen breath test was detected in 2 to 43% of subjects (depending on age group) and was higher in subjects from central and southern Mexico than in subjects from northern Mexico (P < 0.01). Only the experience of major symptoms of intolerance affected milk consumption, and these symptoms were present in 0 to 11% of children > 4 y old and in 7 to 17% of the 13- to 60-y-old subjects. No significant differences were found in lactose maldigestion or milk intolerance between rural and urban populations, but milk consumption was higher in urban areas (P < 0.01). Milk consumption in our study was affected primarily by factors not related to the capacity to digest or tolerate the lactose in milk.

Plants used in Guatemala for the treatment of dermatophytic infections. 2. Evaluation of antifungal activity of seven American plants

From 52 plants screened for antifungal activity, 26 (50%) were active against dermatophytes. This paper reports further evaluation of seven American plants against four pathogenic fungi (Aspergillus flavus, Epidermophyton floccosum, Microsporum gypseum and Trichophyton rubrum), the part showing most activity, the best solvent and, in three cases, the minimal inhibitory concentration (MIC) against the fungus in pure culture. Antifungal activity was confirmed in all of the plants, but not all parts; the most active parts were the bark and leaves. The most active species were Byrsonima crassifolia, Cassia grandis, Gliricidia sepium and Malpighia glabra. Diphysa robinioides, Rhizophora mangle and Cassia occidentalis were less active. The most susceptible fungi were E. floccosum and T. rubrum; A. flavus was not susceptible. Ethanol was usually the best solvent and the MIC of C. grandis, C. occidentalis and D. robinioides was 50 micrograms/ml.

Muir-Torre syndrome associated with a family history of hyperlipidemia

The Muir-Torre syndrome is a rare disorder characterized by sebaceous neoplasms of the skin and multiple visceral malignancies. The syndrome appears to be a familial, autosomal dominant condition. We diagnosed this syndrome in a previously unreported patient and found a personal and family history of malignancies and hyperlipidemia. The association of Muir-Torre syndrome with a family history of hyperlipidemia, another autosomal dominant condition, has not been previously reported. The possible genetic relationship between the two disorders is discussed.

The administration of foot and mouth disease vaccine with oil adjuvant and its influence on the diagnosis of bovine tuberculosis

The possible influence of vaccination with oil adjuvanted foot and mouth disease vaccines on the tuberculin response was investigated in 32 normal guinea pigs and 190 non-tuberculous bovines. Circulating anti-Mycobacterium bovis IgG antibodies were analysed by an enzyme-linked immunosorbent assay (ELISA), in order to determine the effect of the vaccination on the humoral response against mycobacteria in cattle. Control animals were either nonvaccinated or injected with aluminium hydroxide adjuvanted vaccine. Administration of foot and mouth disease vaccine had no apparent influence on the tuberculin responses of either guinea pigs or cattle, nor did it influence the level of anti-M. bovis antibodies in cattle.

Humoral response to Mycobacterium tuberculosis in patients with human immunodeficiency virus infection

The effect of the human immunodeficiency virus (HIV) on mycobacterial antibody production was investigated. Using an enzyme-linked immunosorbent assay (ELISA) for detecting IgG against Mycobacterium tuberculosis PPD, it was observed that individuals at risk of HIV infection show a pattern of humoral response to the tubercle bacillus similar to that previously found in the immunocompetent population not exposed to risk factors: 6 of 12 (50.0%) tuberculosis cases had elevated levels of antibodies to PPD and 27 of 30 (90.0%) asymptomatic individuals had antibody levels within the normal range. In an HIV-seropositive group without AIDS indicator diseases, 8 of 22 (36.4%) tuberculous patients had detectable mycobacterial antibodies whereas 156 of 164 (95.1%) non-tuberculous subjects did not. Among AIDS cases, only 1 of 20 (5.0%) patients with tuberculosis and none of 53 non-tuberculous subjects showed a positive result. The study evidenced an increasing humoral unresponsiveness to PPD in the progression of HIV infection to AIDS. Thus, a serodiagnostic method for detecting tuberculosis such as the ELISA here employed noticeably decreases its utility in the latency stage of the HIV infection, and it is practically useless in clinical AIDS.

[Shortened preoperative preparation in diffuse hyperthyroid goiter: experience in 34 patients]

Conventional preparation of goitrous hyperthyroid patients using lugol and propranolol may take 2 weeks. This period may be shortened using sodium iopodate and dexamethasone. We used 500 mg of sodium iopodate and 1 mg dexamethasone for 4 days in 34 hyperthyroid patients. Surgical indication derived from failure to medical treatment (68%), large goiter (27%) or adverse reaction to PTU (6%). Clinical euthyroidism was achieved after 4 days in all patients. T3 levels decreased from 482 +/- 26.2 to 137.6 +/- 3.7 ng/dl and T4 from 20.6 +/- 1.04 to 15.2 +/- 0.5 micrograms/dl (p < 0.005). Surgery was uneventful in 33 patients, one subject developed supraventricular tachycardia responsive to verapamil. Electron microscopy of the removed thyroid tissue revealed marked decrease of superficial villi and large phagosomes. Thus, sodium iopodate and dexamethasone are effective and safe for preoperative preparation of hyperthyroid patients.

Reciprocal cellular and humoral immune responses in bovine tuberculosis

A sandwich ELISA for the detection of gamma interferon showed higher sensitivity and specificity than an indirect ELISA for mycobacterial antibodies in the diagnosis of bovine tuberculosis. Circumstantial evidence of an inverse relationship between cellular and humoral immune responses to Mycobacterium bovis was found in cattle with natural infection.

Echocardiographic assessment of doxazosin on left ventricular mass in patients with essential hypertension

A single daily dose of doxazosin taken during a 12-week period produced a significant reduction in blood pressure and left ventricular mass index in patients with mild or moderate hypertension. The systolic shortening coefficient was also increased and a trend in the improvement of ejection fraction, rate of circumferential fiber shortening, systolic contraction time, and preejective/ejective ratio was observed. No change in heart rate was recorded and no patients had side effects. The serum lipid profile was modified favorably, particularly with regard to the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio. By producing a reduction in blood pressure and left ventricular mass while favorably modifying the serum lipid profile, doxazosin produced a beneficial change in the overall coronary heart disease risk profile.

Further evaluation of an indirect enzyme-linked immunosorbent assay for the diagnosis of bovine tuberculosis

The sensitivity and specificity of an ELISA for the detection of bovine IgG anti-Mycobacterium bovis antibodies were 73.6% and 94.1%, respectively, as determined in 53 bacteriologically confirmed tuberculous cattle and 101 healthy cattle from a tuberculosis-free area. In addition, the results of ELISA and tuberculin tests in 149 cattle were compared with those of subsequent necropsy studies. Both tests failed to detect 2 animals with tuberculous lesions and positive culture; 3/12 cattle with M. bovis isolation and no lesions, and 2/7 with atypical mycobacterial infection reacted to tuberculin, but none had antibodies; in 128 cattle with neither lesions nor mycobacterial isolation, 6 were tuberculin reactors and 7 others had antibodies. Negative results were obtained by ELISA in 21/22 paratuberculous cattle. Antibodies were not detected in 88.9% to 96.4% of 697 cattle from two tuberculin negative herds of an endemic area. In a herd with proved M. bovis infection, distribution of seropositive animals in tuberculin and non-tuberculin reactors was similar. Antibody responses to cutaneous tuberculin stimuli were observed in 4 experimentally infected cattle, but only in 2/10 healthy controls after repeated PPD stimuli. Nine controls which had either received a single tuberculin dose or none showed no increase in antibody levels. The low sensitivity of this ELISA limits its usefulness as a diagnostic tool for bovine tuberculosis eradication campaigns. However, it could be helpful in epidemiological surveillance if its efficiency to identify infected herds is demonstrated.

[Seroepidemiological study of human hydatidosis, by means of an indirect hemagglutination test in Rio Negro County, X Region, Chile, 1989-1990]

Rio Negro Country (40 degrees 48'-40 degrees 50' South lat.; 73 degrees 12'-73 degrees 13' West long.), is located in the province of Osorno, South of Chile. It has a population of 18,031 inhabitants, with 39% in rural areas. The basic economic activity is cattle raising (cows, pigs). According to reports, prevalence of human hydatidosis in 1988 was 11.1 per 100,000. In order to contribute to a better knowledge of human hydatidosis in Rio Negro County, an indirect hemagglutination test (IHAT) was performed to 509 randomized persons. Five (1.0%) individuals resulted positive.

[Pathologic fracture of the femur due to primary hyperparathyroidism]

Pathologic fractures are not commonly described in primary hyperparathyroidism. A 31 year old male with primary hyperparathyroidism developed severe hypercalcemia and cystic osteitis. Bone pains and a fracture of the femur followed. A parathyroid adenoma was demonstrated by ultrasonography. After resection of the tumor, a normalization of serum Ca levels and clinical recovery took place.