Biomedical subjects
Publications and source records attributed to J Fernandes.
Modern medical technology has made available a complex array of testing methods for drugs of abuse. The gathering of the best information from these methods demands that the clinician be familiar with the different testing protocols. In this, the third article in a monthly series, the authors discuss the more common and useful tests and describe their use for optimal results.
Lyme disease is a common inflammatory disease of North America. It is caused by the spirochetal bacterium Borrelia burgdorferi, which is transmitted by the bite of a small tick, Ixodes dammini. The disease is inconsistent in its manifestation, mimicking a wide variety of maladies, many of which are noninfectious. Currently, there is no practical means for detection of the presence of the organism, and serologic studies offer the best diagnostic aid. High titers of either immunoglobulin G (IgG) or immunoglobulin M (IgM) antibodies to B burgdorferi antigens indicate disease, but lower titers can be misleading. The IgM antibodies may remain after the initial infection, and IgG antibodies may remain for years. Antibiotic therapy early in the infection may interfere with antibody production, but therapy later does not appear to have a significant effect on antibody levels. Because several methods are available for the detection of antibodies and several choices for antibody detected--IgM, IgG, or combinations--the clinical laboratory should provide guidance and advice in choosing and interpreting tests.
Blood glucose self-monitoring offers several advantages. This article, the first in a series, focuses on the types of monitors currently marketed and their limitations. Because optimal patient care rests with operator training, this article also places emphasis on the need to properly train those who will be performing blood glucose monitoring.
The technologic advance that enables measurement of the volume of each red blood cell is available through third-generation hematology analysis. The information generated, expressed as the red blood cell distribution width (RDW), can be diagnostically useful. With the RDW, as with all laboratory data, there can be overlap between distributors of both healthy and anemic persons. Awareness of these limitations can assist the primary care physician in the use of these data.
The anatomical presentations and subsequent biological behavior of mammary cancer reflect the heterogeneity of this tumor. Therapeutic decisions, prognostic indicators and outcome analysis became most meaningful when variations in these tumors are identified. The pathological features that best reflect the biological behavior of mammary cancer that have stood the test of time include tumor invasiveness, tumor size, histologic features, axillary node status, and hormone status. Recent data suggest that DNA ploidy and S-phase analysis not only complement tissue hormonal prognostic factors, but also may be of use in predicting the biological behavior of node-negative patients.
Use of the Papanicolaou smear for screening patients for cervical cancer has reduced the mortality of invasive squamous cell cervical cancer. The continuum of cellular abnormalities leading to invasive carcinoma have been carefully studied through cytologic evaluation. Through this process, terminology has changed, and the concept of cervical intraepithelial neoplasia has developed. Improved reporting of the cytologic abnormalities will not only lead to institution of appropriate therapy but also to a reduction in the number of false-negative results of cytologic studies. Improved communication between the cytopathologist and the attending clinician, as recommended by the Bethesda system, attempts to refine the process of appropriate patient care in the detection and treatment of cervical carcinoma and its precursor states.
In this retrospective study from five centres, 139 patients over 10 years of age with glycogen storage disease types I, III, VI and IX are described. Almost half of the patients with glycogen storage disease type Ia had retarded growth and most had hyperlipidaemia. One-third of the patients had adenomas, although none of these showed malignant transformations. With increasing age the growth, liver size and hyperlipidaemia of patients with glycogen storage disease type III improve. However, there was a high incidence of myopathy and cardiomyopathy. Patients with glycogen storage disease types VI and IX had a normal growth pattern after childhood. Hepatomegaly and hypercholesterolaemia, however, were still present in half of the patients.
We report a longitudinal study of 41 patients with liver glycogenosis due to phosphorylase kinase deficiency. In their youth, patients displayed hepatomegaly (92%), growth retardation (68%), delayed motor development (52%), hypercholesterolaemia (76%), hypertriglyceridaemia (70%), elevation of glutamate pyruvate transaminase (56%) and fasting hyperketosis (44%). With age, these clinical and biochemical abnormalities gradually disappeared and most adult patients were asymptomatic.
Two brothers with benign recurrent intrahepatic cholestasis were studied over a period of 6 years. During this period, 11 episodes of cholestasis were observed, with a mean duration of 2.6 months (range: 2 weeks to 6 months). Once, both brothers developed cholestasis simultaneously. There was a prevalence for episodes of cholestasis in wintertime. The postprandial rise in serum sulfated glycolithocholic acid was increased in the patients, and the bile acid pool was enriched with secondary bile acids. In periods prior to cholestasis, the urinary 3 alpha OH-bile acid concentration was often elevated (greater than 50 mumoles per liter) without a clear correlation with the clinical prodromata. However, it could not be used as a predictor of cholestasis. In contrast, the postprandial rise in serum 3 alpha OH-bile acids was always grossly elevated in periods just before cholestasis. An increase both in fecal bile acid excretion as well as secondary bile acids in the bile acid pool indicated an increased spillover of bile acids into the large bowel. Cholestyramine administered directly after the first signs of cholestasis appeared to shorten an episode of cholestasis. On the other hand, withdrawal of cholestyramine in a cholestasis-free period may have resulted in an episode of cholestasis. Neither taurine supplementation for 3 and 7 weeks nor calcium phosphate, which binds sulfated bile acids in vitro, for 3 weeks could prevent an episode of cholestasis, although the latter normalized the bile acid pool composition. There is a rationale for a fat-restricted diet and cholestyramine therapy only as maintenance treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Fat absorption of an adapted cow's milk formula was studied in a randomized controlled trial involving two groups of 18 premature infants (mean gestational age +/- SD: 33.0 +/- 2.9 weeks, range 26.5-37.5 weeks). The triglyceride configuration was modified by the use of lard. This modification did not improve the absorption of fat or energy. Also no difference in serum concentrations of cholesterol and triglycerides was found. Growth velocity during the study was similar in both groups. Detailed analysis of the data revealed that in infants who received (parenterally) antibiotics (mainly ampicillin and netilmicin) a higher coefficient of fat absorption (+20%, P less than 0.01) and of energy absorption (+8%, P = 0.03) was found. Based on these results, we find no support for the use of lard in adapted cow's milk infant formulas to improve fat absorption. In studies of fat and energy absorption the effects of antibiotics have to be taken into account.
Altered bile acid metabolism has been claimed to play a role in the etiology of benign recurrent intrahepatic cholestasis (BRIC). Therefore, we studied bile acid metabolism in detail in 10 patients with this syndrome. Pool sizes of both primary bile acids were estimated simultaneously, using deuterated cholic acid and chenodeoxycholic acid. The pool sizes of cholic acid and chenodeoxycholic acid, expressed in micromoles per kilogram body weight, were significantly contracted in BRIC patients during a cholestasis-free period: 8.0 +/- 4.2 and 11.7 +/- 4.7, respectively, versus 24.1 +/- 11.7 and 22.9 +/- 7.8 in controls. Fractional turnover rates (per day) for cholic acid and chenodeoxycholic acid were increased: 0.70 +/- 0.29 and 0.58 +/- 0.27, respectively, versus 0.29 +/- 0.12 and 0.23 +/- 0.10 in controls. Bile acid pool composition expressed as percentages in BRIC patients was cholic acid 34 +/- 17, chenodeoxycholic acid 38 +/- 9, deoxycholic acid 27 +/- 18, and lithocholic acid 1 +/- 1, with a glycine to taurine conjugation ratio of 6.7 +/- 4.9. Corresponding values for 32 controls were cholic acid 57 +/- 13, chenodeoxycholic acid 29 +/- 9, deoxycholic acid 14 +/- 9, and lithocholic acid less than 1, with a glycine to taurine conjugation ratio of 2.4 +/- 1.3. Fecal bile acid loss, in micromoles per kilogram body weight per day, was 11.2 +/- 9.0 in BRIC patients compared with 2.8 +/- 1.4 in controls. The serum 7 alpha-hydroxycholesterol level (nanomoles per liter) was significantly increased in BRIC patients: 326 +/- 179 versus 171 +/- 90 in controls. These results suggest that in BRIC patients spillover of bile acids into the colon occurs, which leads to increased fecal bile acid loss and a reduced bile acid pool size. Increased serum 7 alpha-hydroxycholesterol is probably indicative of an accelerated bile acid synthesis rate due to increased activity of cholesterol 7 alpha-hydroxylase, the enzyme catalyzing the first step in the major pathway of bile acid synthesis. The results of our study suggest that in BRIC patients a contracted bile acid pool increases the susceptibility of the liver for cholestatic agents.
The effects of dietary cholesterol and fats on cholesterol metabolism later in life were studied in Mongolian gerbils. Three groups were given a basic diet with soybean oil, palm kernel oil amounting to 8.75% (w/w), or the basic diet only. In three other groups, cholesterol (0.05%) was added to the above diets. Measurements were done in animals of the third generation on the diets. On all diets, teh serum cholesterol of the sucklings was increased as compared to the young that were suckled by mothers on the basic diet only, while body cholesterol was highest in sucklings of mothers on the basic diet or palm-kernel-oil-enriched diets. When the diets were replaced by the basic diets at 6 months of age, serum cholesterol was still increased at 12 months of age in animals previously fed on the cholesterol-enriched diets. Tissue cholesterol did not differ. However, after a challenge with cholesterol at that age, the differences in serum cholesterol were not significantly different.
In 19 patients with a deficiency of glucose-6-phosphatase and 1 patient with a deficiency of glucose-6-phosphate translocase, the effect of nocturnal gastric drip feeding (GDF) on growth and plasma lipids and apolipoproteins was studied. The effect on growth was estimated by determining the height standard deviation score (SDS) of the patients and comparing its changes (delta SDS) over 4-, 2-, and 1-y periods before and 1-, 2-, 5-, and 8-y periods after the institution of GDF. The effect of GDF on plasma lipids and apolipoproteins was investigated by following the concentrations of triglycerides, cholesterol, and apolipoproteins A-I, A-II, B, C-I, C-II, C-III, and E. Growth caught up significantly or remained in the normal range in 14 patients. They were defined as responders to GDF. In the other six patients, growth caught up insufficiently or showed a further deceleration. They were defined as nonresponders to GDF. GDF had only a temporary and marginal effect on plasma lipids and apolipoproteins, but after 5-8 y, the levels of plasma triglycerides, cholesterol, apolipoprotein, B, C-I, C-II, C-III, and E increased further in both responders and nonresponders, whereas apolipoproteins A-I and A-II decreased in nonresponders. There were minor differences in the levels of lipids and apolipoproteins between responders and nonresponders without any discernible trends during the first years of GDF.(ABSTRACT TRUNCATED AT 250 WORDS)
To come to a better understanding of the diet-induced cholesterol-ester storage in the gerbil liver, the reactions of the gerbil to 0.2% of cholesterol in the diet during 4 weeks were compared with those of the rat consuming the same diet. The major reason for the increased hepatic cholesterol-ester storage in the cholesterol-fed gerbil is the low cholesterol turnover in this species. This contrasts with the rat. Although faecal acidic steroid excretion can be slightly increased during cholesterol feeding in the gerbil, this increase is not sufficient to compensate for the quantity of dietary cholesterol when administered at the 0.2% level.
A workshop was held on "Aspects of treatment of patients with glycogen storage disease" within the framework of the Concerted Action "Inborn errors of metabolism" of the European Communities. Consensus was reached on the main issues of treatment of patients with deficiency of glucose-6-phosphatase, glucose-6-phosphate translocase, debranching enzyme, liver phosphorylase and phosphorylase-b-kinase. The resulting recommendations are reported.
Carbohydrates with digestion characteristics between those of lente uncooked starches and rapidly digestible oligosaccharides were administered in a dose of 1.5 g/kg body weight to five patients with glycogenosis from glucose-6-phosphatase deficiency. Postprandial duration of normoglycemia and concentrations of blood insulin and lactate were determined. Uncooked barley groats in water, or incorporated in a meal turned out to behave as lente carbohydrates. Uncooked couscous in water, couscous incorporated in a meal, and partially cooked macaroni given as a meal behaved as semilente carbohydrates as compared with uncooked cornstarch and glucose. The in vitro determination of the digestibility index along with the in vivo tolerance test enables us to choose and incorporate semilente carbohydrates in the day-time treatment of patients.
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Dumping syndrome is rarely seen in children. We studied ten children with symptoms following various types of gastric surgery. All had abnormal blood glucose and breath hydrogen responses after oral glucose challenge, indicating reduction of both glucose tolerance and glucose absorption, as compared to controls. Glucose tolerance was best expressed as the difference between peak and subsequent lowest blood glucose level, the upper limit of normal (mean + 3 SD) being 5.9 mmol/l. In eight children with persisting symptoms we tested the effects of glucomannan, a highly hygroscopic tasteless fibre, on glucose tolerance and glucose absorption. Glucomannan significantly improved glucose tolerance, but did have no overall effect on glucose absorption. Four children tested glucomannan added to the main meals. Breath hydrogen excretion, as established with the daytime breath hydrogen profile, decreased significantly in two, but complaints increased in three children. Glucomannan does not appear to be suitable for the treatment of dumping syndrome in children as the side effects seem to overrule the beneficial effects.