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Biomedical subjects

M Lema

Publications and source records attributed to M Lema.

At least 19 recordsLinked to original sources
PubMed2001

Simultaneous high-performance liquid chromatographic determination of urinary mandelic and phenylglyoxylic acids as indirect evaluation of styrene exposure.

Styrene is rapidly metabolised to mandelic acid (MA) and phenylglyoxylic acid (PGA), which are excreted in urine. In this work, we have developed a simple, sensitive and specific high-performance liquid chromatographic method with minor sample preparation procedures for the simultaneous determination of MA and PGA in urine of workers exposed to styrene. Moreover, urine samples from workers of two plastic factories were analysed, styrene exposure levels of the workers were estimated and data obtained from the two factories were compared.

Chromatography, High Pressure Liquid↗
PubMed2001

Reduction of fecal shedding of enterohemorrhagic Escherichia coli O157:H7 in lambs by feeding microbial feed supplement.

Enterohemorrhagic Escherichia coli O157:H7, an emerging food-borne pathogen, has been implicated in several outbreaks in the US. Ruminants, including cattle, sheep and deer are reservoirs of E. coli O157:H7 and fecal shedding of the pathogen forms the vehicle of entry into the human food chain. We studied the efficacy of Lactobacillus acidophilus, Streptococcus faecium, a mixture of L. acidophilus and S. faecium and a mixture of L. acidophilus, S. faecium, Lactobacillus casei, Lactobacillus fermentum and Lactobacillus plantarum in reducing fecal shedding of E. coli O157:H7 by sheep experimentally infected with the pathogen prior to administration with the microbials. Following oral inoculation with 10(10)CFU of E. coli O157:H7, 30 Suffolk ram lambs were blocked by body weight (six blocks of five lambs each) and lambs within the block randomly assigned to five groups. The lamb groups were fed daily for 7 weeks a basal diet without microbial supplement (control) or the basal diet with L. acidophilus or with S. faecium or with a mixture of L. acidophilus and S. faecium or with a mixture of L. acidophilus, S. faecium, L. casei, L. fermentum and L. plantarum. The microbial supplements contained stabilized live naturally occurring bacteria and were mixed with the diet at the rate of 6.0x10(6)CFU per kilogram of diet. Fecal samples were collected weekly and analyzed for E. coli O157:H7 using modified tryptic soy broth with novobiocin as a pre-enrichement broth and cefixim-tellurite sorbitol MacConkey agar (CT-SMAC) as a selective media. E. coli O157:H7 was confirmed by its reaction with O157 and H7 antisera. E. coli O157:H7 was shed continuously and in varying numbers in the feces throughout the 7-week experimental period by all five groups. However, lambs administered a mixture of L. acidophilus, S. faecium, L. casei, L. fermentum and L. plantarum shed significantly lower (P=0.0211) average number of E. coli O157:H7 (2.3log(10)CFU per gram of feces per week) than the other lamb groups over the entire experimental period. S. faecium supplemented lambs were comparable (P=0.0884) to lambs fed a mixture of L. acidophulus and S. faecium in fecal shedding of the pathogen (3.5 versus 4.4log(10)CFU per gram of feces) but significantly lower (P=0.0001) than the control lambs (5.6log(10)CFU per gram of feces) and those supplemented with L. acidophilus (5.5log(10)CFU per gram of feces). Average daily gain (ADG) and gain to feed ratio (G:F) were significantly improved (P=0.0145) by the mixed culture microbials (163.0g and 0.33 for the control, 186.4g and 0.37 for L. acidophulus, 168.2g and 0.36 for S. faecium, 213.6g and 0.46 for L. acidophulus and S. faecium, and 219.1g and 0.44, respectively for L. acidophilus, S. faecium, L. casei, L. fermentum and L. plantarum supplemented lambs. The study indicates that supplementing lambs infected with E. coli O157:H7 with S. faecium or a mixture of S. faecium, L. acidophilus, L. casei, L. fermentum and L. plantarum in the diet can reduce total number of E. coli O157:H7 shed in the feces and improve animal meat production performance as well.

Journal Article↗
PubMed2001

Clinically manifested major health problems of crossbred dairy herds in urban and periurban production systems in the central highlands of Ethiopia.

The major clinical diseases of crossbred dairy herds were investigated for two years in a milk shed in Addis Ababa. Animals in 38 herds were randomly selected and visited weekly. Diagnosis of diseases and causes of death were based on clinical observation. Disease conditions were categorized into 8 groups, the mean annual incidence for all diseases being 44.7%. Reproductive diseases and clinical mastitis were most frequently observed, whereas gastrointestinal disorders, respiratory tract diseases, locomotor disorders and metabolic diseases each occurred in less than 5% of the cattle. Specific infectious and miscellaneous disease conditions each had annual incidence of about 6%. Cows and young stock were most affected and diseases were more frequent in urban situations than in periurban situations. Herd size and season significantly influenced the incidence of disease but study year did not. The crude mortality rate was 4.2%.

Animals↗
PubMed2000

Lamb production and forage quality under a forage system consisting of AU Triumph tall fescue and Tifton 44 bermudagrass.

The lamb production potential and forage quality of a forage system consisting of AU Triumph fescue and Tifton 44 bermudagrass was studied over a period of two consecutive years. Each spring, 60 yearling Suffolk ewes and 40 wethers were divided into two groups and allowed to graze two replicated 1ha AU Triumph paddocks continuously. At the end of the spring grazing season, both groups were transferred to two replicated 1ha Tifton 44 paddocks for summer grazing. Body weight was recorded fortnightly and composite forage samples analyzed for chemical composition, in vitro dry matter disappearance (IVDMD) and in vitro organic matter disappearance (IVOMD) at the end of the study. Mean crude protein (CP), ether extract (EE), ash, neutral-detergent fiber (NDF), acid-detergent fiber (ADF), cellulose, lignin, IVDMD and IVOMD contents of AU Triumph fescue were 13.26, 1.86, 7.38, 69.4, 36.37, 29.2, 6.81, 64.44 and 62.88%, respectively. The corresponding values for Tifton 44 bermudagrass were 7.5, 1.01, 5.2, 78.3, 41.0, 28.3, 8.8, 56.97 and 55.61%. Average daily gain (ADG) and lamb gain per hectare on AU Triumph fescue were 142.1g and 412.59kg/ha, respectively. However, lamb ADG started to decline and remained low when they were transferred from AU Triumph to Tifton 44 bermudagrass resulting in a low ADG and lamb gain per hectare of only 18.2g and 84.09kg/ha, respectively. In contrast, Tifton 44 yielded higher post grazing residual DM, suggesting that the decline in performance of the lambs grazing Tifton 44 to be related to poor forage quality rather than availability. The results indicate that low nutritive value of Tiftton 44 bermudagrass is a limiting factor to lamb production in the forage system studied. To prevent the observed decline in lamb performance, it might be necessary to fertilize Tifton 44 at a higher rate or replace it with a better quality warm season forage.

Journal Article↗
PubMed2000

Assessing microsatellite instability with semiautomated fluorescent technology: application to the analysis of primary brain tumors.

The replication error phenotype, revealed by the observation of widespread microsatellite instability (MIN), has been identified as a new mechanism of cancer susceptibility, and the comparison of the allele sizes of polymorphic microsatellite repeats between normal and tumor DNA is now frequently undertaken in colorectal and other human neoplasias. The lack of precise characterization of the electrophoretic profiles of microsatellites is one of the main sources of discord between the rate of MIN reported for the same type of tumor by different investigators. The recent introduction of fluorescent-based semiautomated microsatellite analysis allows a more accurate size comparison, but one or more artificial peaks, generated during polymerase chain reaction (PCR) and/or electrophoresis, are frequently detected along with the true allele peaks. The aim of this study was to characterize the most frequent artificial extra peaks in the short tandem repeats (STRs) used by us to assess MIN in human cancers. We analyzed eight microsatellite loci in 113 primary brain tumors. HumFibra/FGA exhibited the most frequent extra peak formation. For each microsatellite there is a characteristic pattern of artifact formation which must be recognized to avoid a false-positive diagnosis of MIN.

Automation↗
PubMed2000

Synthesis and herbicidal activity of N-oxide derivatives.

As part of an ongoing program on the chemistry and biological activity of N-oxide-containing molecules, a number of novel 1,2, 5-oxadiazole N-oxide, benzo[1,2-c]1,2,5-oxadiazole N-oxide, and quinoxaline N,N'-dioxide derivatives were synthesized and evaluated for their herbicidal activity. Many of these compounds exhibited moderate to good herbicidal pre-emergence activity against Triticum aestivum. Dose-response studies were done on the more representative compounds (12, 20, and 26). The most active compound, butylcarbamoylbenzo[1,2-c]1,2,5-oxadiazole N-oxide, 26, displayed herbicidal activity at concentrations as low as 24 g/ha.

Dose-Response Relationship, Drug↗
PubMed2000

Low frequency of replication errors in primary nervous system tumours.

OBJECTIVES: Automated DNA technology was used to analyze the incidence of microsatellite instability (MIN) among the most frequent types of adult primary CNS tumours and to determine its relation with clinicopathological characteristics. METHODS: Fifty six gliomas, 32 meningiomas and 11 schwannomas were screened for size changes at eight microsatellite loci using fluorescent polymerase chain reaction (PCR) followed by fragment analysis in an automated sequencer. A tumour was considered as MIN+ when a different electrophoretic pattern between constitutional and tumour DNA was evidenced in one or more microsatellite markers and as replication error positive (RER+) when at least 25% of the markers analyzed (2/8) showed instability. The MIN phenotype was correlated with relevant clinical and pathological parameters. RESULTS: Globally, instability was found in 19/767 analyses (2.47%), with a higher rate among tetranuceotide than dinucleotide repeats (chi(2) test, p=0.018). Ten gliomas (17.9%), two meningiomas (6.3%), and two schwannomas (18.2%) were MIN+, whereas one glioma (1.8%), two meningiomas (6.3%), and one schwannoma (9.1%) were classified as RER+. A possible association between microsatellite instability and a shorter duration of clinical course was found in meningiomas. The MIN+ phenotype was more frequent in spinal than intracranial schwannomas (Fisher's exact test, p=0.018). No other significant association with clinical or histological features was detected. CONCLUSIONS: Although microsatellite instability can be demonstrated at a low rate in some primary CNS tumours, a true replication error phenotype (revealed by widespread microsatellite instability at numerous loci) is uncommon and unlikely to play an important part in the pathogenesis of these neoplasms. This form of instability was more frequent in tetranucleotide than in dinucleotide repeats. To our knowledge, this is the first report of MIN in schwannomas, where it was associated with the spinal localisation of the tumour.

Adult↗
PubMed1999

Characteristics of postradical neck pain syndrome: a report of 25 cases.

The postradical neck pain syndrome has been briefly described in the literature, but detailed characterization has not been reported. To further define this syndrome, 25 patients with persistent pain for at least 1 month following neck dissection were evaluated. The sample consisted of 13 men and 12 women with moderate to severe pain ranging from 1 month to 27 years in duration. All patients had at least one type of neuropathic pain: spontaneous, continuous burning pain (81%), shooting pain (69%), and/or allodynia (88%). Neuropathic pain sites were within the distribution of the superficial cervical plexus (SCP). Regional myofascial pain was also common (72%). Seventeen patients agreed to undergo diagnostic local anesthetic injections. Ten of these patients had both neuropathic and somatic (myofascial) pain. Local anesthetic injection of the SCP temporarily eliminated all neuropathic pain in the 17 patients who underwent the procedure. The 10 patients who also had myofascial pain reported temporary relief of their somatic pain following myofascial trigger point injections (TPI). Criteria for the postradical neck pain syndrome are proposed: (1) persistent, nonprogressive neuropathic pain involving one or more branches of the SCP, which may be accompanied by (2) regional nonprogressive somatic pain associated with myofascial pain trigger points in head and neck muscles.

Female↗
PubMed1998

Proglumide as a morphine adjunct in cancer pain management.

Proglumide, a cholecystokinin (CCK) antagonist, has been shown to have agonist effects at extremely low doses on both endogenous and exogenous opioid systems. To determine the effectiveness and the side effects of proglumide as an opioid agonist, a double-blind crossover study was conducted in 60 patients with cancer pain who were treated with opioid analgesics. Forty-three patients completed both treatment arms: (a) full analgesic dose plus placebo (the patient's usual analgesic dose, individualized to drug dose and route) and (b) one-half analgesic dose plus 50 mg of proglumide. An analysis of eight pain descriptors was performed to determine whether or not these treatments were associated with a difference in patients' pain perception. The level of patient anxiety differed between the two arms, but was inconsistent over time. There were no side effects detected with proglumide, as determined by clinical monitoring and patient questionnaire. No differences in pain perception were detected between the study arms. The latter finding is consistent with an augmentation of morphine analgesia, but without additional controls, the equivalency of the two arms cannot be determined with certainty. Nonetheless, this study suggests that proglumide may have use as an opioid adjunct in patients with cancer pain.

Analgesics, Opioid↗
PubMed1998

[Time for cerebral damage due to hyperglycemia in acute ischemia].

INTRODUCTION: Hyperglycemia increases morbimortality in cerebral infarcts. In animal models, this relationship is only seen during the initial moments of cerebral ischaemia. The time needed in humans for cerebral damage to occur due to hyperglycemia is not known. MATERIAL AND METHODS: We included 194 patients admitted within 24 hours of the start of their first clinical episode of cerebral hemisphere infarction. The glucemia was determined on admission and after 24, 48 and 72 hours. The neurological defect was evaluated on the Canadian scale on the seventh day. The volume of the infarct was determined on a second CT scan done between the fourth and seventh days after the episode. RESULTS: There was a positive association between the volume of the infarct and the glycemias on admission and after 24 hours, but this was not seen in later determinations. The difference in scoring, on the Canadian scale, on the seventh day, between patients with glycemias above or below 120 mg/dl decreased from the time of admission up to the time samples were taken 72 hours later. However, statistical significance persisted during the whole period studied. Nevertheless, in a logistic regression model, the glycemia on admission was the only determination associated with the Canadian scale on the seventh day (OR = 1.02; IC 95% = 1.01-1.02). CONCLUSIONS: There is a clear association between hyperglycemia and the worst stage of the infarct, and this is most intense in the first hours after onset of the clinical features.

Acute Disease↗
PubMed1998

[Comparison of hypertensive and non-hypertensive lacunar infarcts].

INTRODUCTION: Arterial hypertension and hypohyalinosis of the arterias perforantes are said to be the commonest cause of lacunar infarcts, although other etiological factors and anatomo-pathological lesions are described more and more frequently. We designed a study to compare the clinical topographic and prognostic characteristics of patients with hypertensive and non-hypertensive lacunar infarcts. MATERIAL AND METHODS: We selected 51 patients with lacunar infarcts: in 23 (45%) arterial hypertension was the only etiological factor recognized. In 28 (55%) other risk factors (16 diabetes mellitus, 17 cardiopathy, 8 hyperlipemia, 13 cigarette smoking and 11 alcoholism) were seen. We evaluated the form of presentation, the type of infarct and whether this was associated with headache. The degree of defect was determined on admission using the Canadian scale. The size of the infarct was measured on CT or RM, using whichever measurement was greater. The evolution of the condition was determined on the Canadian scale and the index of Barthel after three months. RESULTS: Age and sex distribution was similar to both groups. Motor hemiparesia was the commonest lacunar syndrome and the distribution was similar. There was no difference in form of onset, association with headache or neurological defect between the hypertensive and non-hypertensive lacunar infarcts. The topographical distribution, the presentation of single or multiple lesions, the size of the infarcts and the prognosis were similar in both groups. CONCLUSIONS: Lacunar infarcts, whether hypertensive or not, show no differences regarding clinical, neuro-radiological or evolutionary characteristics.

Aged↗
PubMed1997

[A study of bilingual Galician-Castillian aphasic patients].

INTRODUCTION: Aphasia in bilingual persons has some striking peculiarities. Most studies have been carried out in mono-lingual societies, where the second language has usually been learnt after immigration. In Galicia, linguistic closeness and simultaneous learning of Galician and Castilian languages permits the testing of neuropsychological theories conceived in other circumstances. OBJECTIVE: In aphasic bilingual Galician-Castilian patients we studied how this affected denomination, designation and translation, different modes of recovery, variables associated with differential affectation, the presence and influence of specific phenomena of aphasia in bilingual persons on changes in dominance and mixing of the languages. Material and methods. We selected 49 patients, 29 men and 20 women aged between 32 and 85 years old. We analyzed the variables associated with differential affectation: types of aphasia, size and site of the lesion, aetiology, age, educational level, and the presence and influence of phenomena specific to aphasia in bilingual persons. RESULTS: The test most affected was translation, to a lesser extent denomination, and finally designation. Capacity for recovery is greater in the dominant language. Translation recovers better than denomination and this better than designation. We found no changes in dominance, no selective loss of either language but have seen some interference in the non-dominant language. CONCLUSIONS: The two languages are seen to be recovered equally, as were other languages previously studied in aphasiology.

Adult↗
PubMed1997

[Familial strio-pallido++-dentate calcification].

INTRODUCTION: Calcification of the dentate nucleus of the cerebellum may be seen on cerebral CT in 0.3-0.5% of patients with no symptoms or extra-pyramidal signs. Although there are many causes, some cases show a family incidence. Clinical cases. We present two cases, mother and son, in whom the predominant clinical findings were poor language and a bilateral extrapyramidal syndrome. Laboratory tests, hormone and immunological studies were normal. In both patients cerebral CT showed bilateral calcification of the basal nuclei and dentate nuclei of the cerebellum. DISCUSSION: Our patients fulfilled the clinical and neuro-imaging criteria described in familial strio-pallido-dentate calcification. There is no relationship between the duration and intensity of symptoms, and the extension of the calcification. However, all patients with calcification show clinical features. The predominant features are poor language and a bilateral extra-pyramidal syndrome. These observations indicate that in patients with calcification of the basal ganglia and dentate nuclei of the cerebellum it is necessary to study first degree relatives in order to identify the condition.

Aged↗
PubMed1996

Changes in serotonin level and turnover in discrete hypothalamic nuclei after pinealectomy and melatonin administration to rats.

The influence of the pineal gland on the hypothalamic serotonergic function was examined by studying the effects of long-term pinealectomy (1 month) and melatonin replacement (500 micrograms/kg; 10 days) on serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) content as well as on the in vivo 5-HT synthesis rate in discrete hypothalamic nuclei. Pinealectomy was followed by a significant decrease of 5-HT content in the anterior hypothalamic nuclei (AHN) and the ventromedial hypothalamic nuclei (VMHN), and also in 5-HIAA content in lateral (LPON) and medial preoptic nuclei (MPON). The 5-HT synthesis rate, estimated from the accumulation of 5-hydroxytryptophan after blockade of the 1-amino acid decarboxylase activity, were also decreased in the AHN and the paraventricular hypothalamic nuclei (PVHN) of pinealectomized rats. In contrast, an enhanced 5-HT synthesis rate and basal 5-HIAA content were found in the suprachiasmatic nuclei (SCN) after pinealectomy. Daily treatment with melatonin for 10 days reversed most of the effects induced by pinealectomy. Thus, melatonin increased the levels of 5-HT in the AHN and VMHN, and slightly increased the 5-HIAA content in preoptic nuclei. In addition, melatonin increased the 5-HT synthesis rate in the AHN and VMHN, but also in the MPON, VMHN and dorsomedial hypothalamic nuclei (DMHN) where pinealectomy had no effect. By contrast, melatonin treatment did not affect SCN 5-HT synthesis rate, although it decreased 5-HIAA levels. The results demonstrate that melatonin is able to stimulate 5-HT metabolism in most of the hypothalamic areas, but inhibits SCN 5-HT function. Some of the effects of melatonin seems to be exerted by modulating the synthesis of the amine, although melatonin likely also interacts with other regulatory processes of 5-HT function (i.e. release/uptake). The well defined presence of melatonin receptors in the rat SCN, and its absence in other hypothalamic structures, suggest that this may be the mechanism mediating the differential response to endogenous melatonin. Moreover, the larger effect of exogenous melatonin in relation to pinealectomy suggests the presence of melatonin unespecific effects possibly owing to supraphysiological doses. The present findings may be relevant for the mode of action of melatonin and its implication in several endocrine and behavioral functions mediated by serotonergic neurons.

Animals↗
PubMed1996

Cerebrospinal fluid tyrosine and 3,4-dihydroxyphenylacetic acid levels in migraine patients.

We studied biochemical parameters related with central dopaminergic neurotransmission in migraine patients during crisis. We determined tyrosine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in cerebrospinal fluid (CSF) of 47 patients, 29 suffering migraine without aura and 18 suffering migraine with aura, comparing them with 27 control subjects. Tyrosine levels did not differ significantly between patients and controls. The CSF concentration of DOPAC was 0.73 +/- 0.55 ng/ml in the control population, 3.84 +/- 2.08 ng/ml in patients with migraine without aura and 3.30 +/- 1.49 ng/ml in patients suffering migraine with aura. The concentration of DOPAC correlated positively with the intensity of headache. These results suggest that patients with migraine have a central dopaminergic hyperfunction, probably related to a coexisting central dysfunction of noradrenergic neurotransmission.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1996

[The prognostic value of analytical hemorheological factors in stroke].

Plasmatic hyperviscosity is a known vascular risk factor which depends, among other parameters, upon total proteins, haematocrit value and fibrinogen. The aim of this study was to determine the relationship between these analytical haemorrological parameters and mortality and acute stroke sickness rate. We studied 216 patients with brain infarct and spontaneous intracerebral haemorrhage out of a sample of 256 acute stroke patients. We evaluated neurological affectation using the Canadian scale upon admission, on the seventh day and after three months. We determined plasmatic haemorrological factors (haematocrit, fibrinogen and total proteins) upon admission and again after one week and then at three months High fibrinogen levels in plasma were related to brain infarct mortality regardless of the cause of death.

Adult↗
PubMed1996

[3 year survival in patients hospitalized for acute cerebrovascular disorders].

For three years we studied the mortality and functional situation of all patients admitted in 1991 to the Neurology Service suffering from acute stroke with the exception of subarachnoid haemorrhage cases. We analyzed the cause of death whether directly related to the initial illness or not. Out of 134 patients admitted for acute stroke, 48 (41.02% of the 117 patients examined after excluding 17 whom we did not obtain complete information from) had died after three years. The main causes of death were directly related to acute stroke (37.5%) and pneumonia (37.5%). Death occurred mainly in the first month (79.16% of deaths). Predictive variables for mortality directly related to acute stroke during the first month include severe weakness, brain haemorrhage, dysphasia and earlier incidence of acute stroke. Variables related to higher mortality rate due to other causes in the first month were dysphasia, age and angina antecedents, whereas earlier incidence of acute stroke was associated with a lesser mortality rate for these causes, as distinct from acute stroke itself. Greater levels of weakness and sphincteral incontinence are the best predictive signs of dependency functional situation at the end of the first month and, along with diabetes, after one and three years.

Acute Disease↗