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Biomedical subjects

R J Wynn

Publications and source records attributed to R J Wynn.

16 recordsLinked to original sources

White blood cell left shift in a neonate: a case of mistaken identity.

We present a full-term male infant who presented with tachypnea and an increased band count on his complete blood count (CBC) with an immature to total neutrophil (I:T) ratio of 0.6 raising suspicion of early onset sepsis. A blood culture was drawn and he was started on appropriate antibiotics. The patient's clinical condition rapidly improved; however, the white cell count 'left shift' persisted. When a detailed family history was obtained, it was discovered that the father, paternal uncle and the grandfather had been diagnosed with Pelger-Huet anomaly (PHA). As the urine, blood and CSF cultures were all negative in this now well-appearing infant, the left shift on the CBC was believed to be due to inheritance of the PHA. We present this case to emphasize that even in this age of sophisticated laboratory evaluation, a good clinical history, including family history, and clinical evaluation, are essential for accurate diagnosis.

Diagnostic Errors↗

Effect of feeding rumen-protected conjugated linoleic acid on carcass characteristics and fatty acid composition of sheep tissues.

Two experiments were conducted to determine the effectiveness of a rumen-protected CLA (pCLA) supplement and the impact of feeding this pCLA on carcass characteristics and tissue fatty acid composition of lambs. In Exp. 1, a CLA-80 preparation (80% pure CLA; contained similar proportions of cis-9, trans-11, and trans-10, cis-12 CLA), protected against rumen degradation, was fed to sheep, and the proportion of CLA reaching the duodenum was determined. A 3 x 3 Latin square design was used with 3 diets (1.4 kg of concentrate-based control diet, the same control diet plus 22 g of CLA-80, or the same control diet plus 110 g of pCLA/d), 3 feeding periods, and 3 rumen and duodenally cannulated sheep (Mule x Charolais males, 10 mo of age, BW 55.3 +/- 1.8 kg). After 7 d of feeding, sheep were ruminally infused with chromium EDTA and Yb acetate for 7 d, after which samples of duodenal digesta were collected every 6 h for 48 h to determine the quantity of CLA reaching the small intestine each day. The amounts of CLA cis-9, trans-11 and trans-10, cis-12, and combined isomers, flowing through the duodenum each day were greater (P = 0.01) in sheep fed pCLA. Approximately 65% of the pCLA avoided rumen biohydrogenation, with the ratio of the 2 main isomers remaining similar. In Exp. 2, 36 Mule x Charolais ewe lambs (approximately 13-wk old, average initial BW 29.3 kg) were fed 3 levels of the pCLA or Megalac, which were fed to provide an equivalent energy content at each pCLA level. Lambs were randomly assigned to 1 of 7 treatment groups, which were fed for 10 wk to achieve a growth rate of 180 g/d. Treatments included the basal diet and the basal diet plus 25, 50, or 100 g of pCLA/kg of diet or the equivalent amount of Megalac. In liver (P < 0.001) and all adipose tissue depots studied, the proportions of both CLA isomers increased (P = 0.02) with the amount of pCLA fed but were not altered with increasing of Megalac. Although there was no effect of treatment on cis-9, trans-11 CLA content, accumulation (P < 0.001) in the LM with increasing of pCLA supplementation was observed for the trans-10, cis-12 isomer. Although tissues had been enriched with CLA, there was no evidence of a reduction in adipose tissue or an increase in muscle mass in these sheep. However, an effect of pCLA on tissue fatty acid composition was consistent with an inhibition of stearoyl-CoA desaturase.

Acetyl-CoA Carboxylase↗

Differing effects of forage and concentrate diets on the oleic acid and conjugated linoleic acid content of sheep tissues: the role of stearoyl-CoA desaturase.

Feeding sheep concentrate-based diets increases the oleic acid content of their tissues, whereas the cis-9, trans-11 conjugated linoleic acid (CLA) content is increased by feeding forage diets. Both these metabolic transformations could be attributable to increased activity of stearoyl-CoA desaturase (SCD). Therefore, the effect of forage or concentrate feeding regimens on the fatty acid composition of sheep tissues were investigated to determine whether any changes are related to an alteration of SCD mRNA levels. Twenty-four ewe lambs were randomly allotted to one of three dietary treatment groups: 1) dehydrated grass pellets, 2) concentrate diet fed to achieve a growth rate similar to that of the dehydrated grass pellets, and 3) the same concentrate diet approaching ad libitum intake. As expected, animals fed ad libitum concentrates grew at a greater (P = 0.001) rate (280 g/d) than those fed either of the other two diets (180 g/d), which were similar. In samples of liver and the three adipose tissue depots studied, the concentration of oleic acid from sheep fed either level of the concentrate diet was greater (P < 0.001) than from animals fed forage. This was associated with an increase (P < 0.05) in the ratio of SCD to acetyl-CoA carboxylase mRNA in adipose tissue and liver. Compared with concentrate-fed, the forage-fed lambs had increased (P < 0.05) levels of the cis-9, trans-11 isomer of CLA and C18:1, trans-11 in all their tissues, although the levels of SCD mRNA were lower. It therefore seems that the increased oleic acid content of sheep tissues in response to concentrate-rich diets is associated with an increase in SCD gene expression. By contrast, the increased concentration of CLA in animals fed forage-based diets is associated with an increase in substrate (C18:1 trans-11) availability.

Abomasum↗

The pharmacokinetics and metabolism of cimetidine in neonates.

Cimetidine pharmacokinetics and metabolism were studied in 2 full-term and 1 premature neonates. All infants demonstrated the capacity to eliminate cimetidine via both metabolic and renal routes. The half-life of cimetidine ranged from 3.4 to 2.1 h, and decreased as total body clearance increased. These alterations in pharmacokinetics were felt to represent developmental and maturational differences, primarily in renal function. In contrast to the 60% routinely seen in adults, approximately 90% of the administered dose was recovered in the urine of the full-term infants as cimetidine and its known metabolites. Cimetidine sulfoxide and hydroxymethyl cimetidine were detected in the serum and urine of 2 patients, and the elimination half-life of these metabolites was two- to threefold longer than values seen for cimetidine. During multiple dosing of cimetidine, significant accumulation of cimetidine metabolites may be expected. The reported dose of 15-20 mg/kg/day is adequate in full-term neonates, however, it appears that premature infants and those with renal dysfunction may require lower dosing rates.

Biotransformation↗

High gentamicin trough concentrations in neonates of less than 28 weeks gestational age.

77 newborns, ranging from 25.5 to 43 weeks gestational age (GA) and receiving gentamicin, were studied prospectively over 4 months. Peak and trough serum concentrations were obtained on days 1, 3, and 5 of therapy. Gentamicin, 2.5 mg/kg/dose, was given at intervals according to GA. 63% of newborns of less than 28 weeks on doses of gentamicin of 2.5 mg/kg every 24 h (q24h), 75% of less than 28 weeks on gentamicin q18h, 90% of newborns of 23-34 weeks (on q18h), and 82% of those of greater than 34 weeks GA (on q12h) had serum gentamicin trough concentrations less than or equal to 2.0 micrograms/ml on day 1. By day 3, 5/5 newborns of less than 28 weeks (q18h) had trough concentrations greater than 2.0 micrograms/ml, whereas only 20% of those on the q24h regimen had high trough concentrations (p less than 0.05). Possible risk factors associated with altered gentamicin disposition in neonates are discussed.

Bacterial Infections↗

Brief clinical report: an infant with duplication of 17q21 lead to 17qter.

Duplication of the distal part of 17q has been reported in 4 patients [1,2]. We are reporting clinical, autopsy, and cytogenetic data on an additional patient whose condition was due to a familial translocation in which the patient's chromosome constitution is 46,XX, der(4),t(4;17)(p16;q21) pat. The phenotype of the five known patients with this duplication is very similar, and their manifestations are distinct enough to be clinically recognizable. Abnormalities common to all five patients are severe growth impairment, craniofacial anomalies with severe hypertelorism, frontal bossing and temporal narrowness, a widow's peak, narrow palpebral fissures, a thin upper lip overlapping a thin lower lip with down-turned corners of the mouth, micrognathia, apparently low-set and deformed ears, short webbed neck, and hyperlaxity of the limbs.

Abnormalities, Multiple↗

An infant with trisomy 6q21 leads to 6qter.

A female who died shortly after birth with multiple congenital anomalies corresponding to the clinical picture of partial 6q trisomy is described and the autopsy findings are presented. The patient had an unbalanced chromosome complement with a 6q21 leads to 6qter duplication. Her mother is a balanced 46,XX,t(6;10)(q21;q26) carrier.

Chromosomes, Human, 6-12 and X↗

Starvation with hypernatremic dehydration in two breast-fed infants.

Unrecognized breast feeding malnutrition may rapidly lead to life-threatening or neurologically devastating consequences. With the increased interest in lactation, it is important that physicians, dietitians, and nurses provide counseling to parents regarding the benefits and difficulties of breast feeding. Appropriate education, assessment of the infant's vigor and maternal milk supply prior to release from the hospital, and close follow-up evaluation are all necessary to help a mother feed successfully, to detect a developing problem, and to avert a potentially serious condition in the baby.

Breast Feeding↗

Neonatal E. coli pericarditis.

A review of the literature reveals only one case of neonatal Escherichia coli pericarditis. This is a case report of Escherichia coli pericarditis occurring in a two day old infant. The infant initially presented with lethargy and jaundice but this rapidly progressed into shock. Despite vigorous resuscitative efforts, the infant succumbed and at autopsy 30 cc of purulent fluid were obtained. Cultures of the admission blood and post-mortem pericardial effusion grew Escherichia coli. The clinical diagnosis of pericarditis is often difficult because of vague, nonspecific symptoms and signs. The symptoms are usually those of sepsis plus those of impaired circulation due to mechanical embarrassment by accumulating pericardial effusion. It is difficult to differentiate pericarditis with effusion from myocarditis and pericardial effusion secondary to congestive heart failure. The use of pericardiocentesis as a diagnostic tool and echocardiography are the most helpful techniques presently available for diagnosis. Management consists of vigorous supportive efforts, antibiotics, and drainage of the pericardial effusion. Because of the very high mortality associated with this disorder, a high index of suspicion with a vigorous diagnostic and therapeutic approach to the patient is indicated.

Escherichia coli Infections↗