Search PubMed⌕ Search

Biomedical subjects

K Cunningham

Publications and source records attributed to K Cunningham.

At least 19 recordsLinked to original sources
PubMed1995

Precision and accuracy of clinical and radiological signs in premature infants at risk of patent ductus arteriosus.

OBJECTIVE: To determine the precision (interobserver agreement) and accuracy (agreement with criterion standard) of clinical and radiological signs in premature infants at risk of patent ductus arteriosus (PDA) with left-to-right shunting. DESIGN: Masked comparison of clinical and radiological examination with Doppler flow echocardiography (criterion standard). SETTING: Neonatal intensive care unit. PATIENTS: One hundred infants with birth weights less than 1750 g were studied once between days 3 and 7 of life. A third of the cohort was intubated at the time of study. INTERVENTION: Five independent observers noted the presence or absence of an increased pulse volume, an active precordium, a heart murmur, a cardiothoracic ratio greater than 60%, increased pulmonary vascular markings on a concurrent chest x-ray film, and a relative increase of the cardiothoracic ratio compared with that from the previous chest x-ray film. Pulsed and color flow Doppler echocardiography was performed within 4 hours. All 100 tapes were reviewed by a second pediatric cardiologist. RESULTS: Twenty-three infants had a PDA with left-to-right shunting. The precision of clinical signs was modest, with average kappa values of 0.15 for pulse volume, 0.32 for precordium, and 0.41 for murmur. Pulse quality (43%) and murmur (42%) had the highest mean sensitivities. Corresponding specificities were 74% for pulse volume and 87% for murmur. The combination of a cardiac murmur with an abnormal pulse volume had the highest positive predictive value (77%). The radiological examination did not improve the observers' ability to distinguish between patients with and without PDA. CONCLUSIONS: The precision and accuracy of clinical and radiological signs of a PDA with left-to-right shunting are unsatisfactory. Therefore, Doppler flow echocardiography is required to diagnose PDA confidently in preterm infants between days 3 and 7 of life.

Ductus Arteriosus, Patent↗
PubMed1994

The colicin A pore-forming domain fused to mitochondrial intermembrane space sorting signals can be functionally inserted into the Escherichia coli plasma membrane by a mechanism that bypasses the Tol proteins.

Colicin A is a pore-forming bacteriocin that depends upon the Tol proteins in order to be transported from its receptor at the outer membrane surface to its target, the inner membrane. The presequence of yeast mitochondria cytochrome c1 (pc1) as well as the first 167 amino acids of cytochrome b2 (pb2) were fused to the pore-forming domain of colicin A (pfColA). Both hybrid proteins (pc1-pfCoIA and pb2-pfColA) were cytotoxic for Escherichia coli strains devoid of colicin A immunity protein whereas the pore-forming domain without presequence had no lethal effect. The entire precursors and their processed forms were found entirely associated with the bacterial inner membrane and their cytotoxicities were related to their pore-forming activities. The proteins were also shown to kill the tol bacterial strains, which are unable to transport colicins. In addition, we showed that both the cytochrome c1 presequence fused to the dihydrofolate reductase (pc1-DHFR) and the cytochrome c1 presequence moiety of pc1-pfCoIA were translocated across inverted membrane vesicles. Our results indicated that: (i) pc1-pfCoIA produced in the cell cytoplasm was able to assemble in the inner membrane by a mechanism independent of the tol genes; (ii) the inserted pore-forming domain had a channel activity; and (iii) this channel activity was inhibited within the membrane by the immunity protein.

Amino Acid Sequence↗
PubMed1994

The role of the gut in regulating food intake in man.

In addition to various psychosocial and metabolic factors, food intake is also influenced by gastrointestinal mechanisms that trigger both the initiation and termination of eating behaviors. Although gastric distension is one of the most obvious signs of "fullness" and clearly plays a role in controlling food intake, its effects are only temporary and are distinct from the feelings of satiety generally associated with a meal. Such postprandial sensations appear to be related to the activation of intestinal chemoreceptors. Other evidence indicates that the release of cholecystokinin and perhaps other transmitters as well may contribute to satiety. Although the stomach probably does not expand or shrink in response to different levels of food intake, nutrient receptors in the small intestine probably do adapt to changes in food intake. Intestinal adaptation also occurs in response to thyroid hormone, insulin, and cortisol as well as to obesity, pregnancy, and illness, which all may have an important bearing on changes in eating behavior in these situations.

Cholecystokinin↗
PubMed1994

Internal carotid artery dissection after remote surgery. Iatrogenic complications of anesthesia.

BACKGROUND: Subintimal dissection with acute occlusion of the internal carotid artery resulting in acute cerebral infarction has not been reported as an iatrogenic complication of general anesthesia. CASE DESCRIPTIONS: An anesthetist stretched the neck of a 44-year-old man by anchoring an anesthesia mask posterior to the angle of the jaw with overlying fingers as the patient struggled during an insufficient inhalational mask anesthetic. A 33-year-old man received an endotracheal anesthetic without struggle, but as he was turned from a supine to a prone position, his head and neck were not immobilized to rotate with his torso during the move. The next day both patients suffered acute cerebral infarctions secondary to ICA dissections and occlusions (angiographically demonstrated). CONCLUSIONS: Stretching the soft neck tissues of anesthetized patients can cause internal carotid artery dissection and acute cerebral infarction.

Adult↗
PubMed1992

Cytochromes c1 and b2 are sorted to the intermembrane space of yeast mitochondria by a stop-transfer mechanism.

The pathway by which cytochromes c1 and b2 reach the mitochondrial intermembrane space has been controversial. According to the "conservative sorting" hypothesis, these proteins are first imported across both outer and inner membranes into the matrix, and then are retranslocated across the inner membrane. Our data argue against this model: import intermediates of cytochromes c1 and b2 were found only outside the inner membrane; maturation of these proteins was independent of the matrix-localized hsp60 chaperone; and dihydrofolate reductase linked to the presequence of either cytochrome was imported to the intermembrane space in the absence of ATP. We conclude that cytochromes c1 and b2 are sorted by a mechanism in which translocation through the inner membrane is arrested by a "stop-transfer" signal in the presequence. The arrested intermediates may be associated with a proteinaceous channel in the inner membrane.

Adenosine Triphosphate↗
PubMed1992

Obsessive-compulsive disorder in Huntington's disease.

Two patients with Huntington's disease (HD) and obsessive-compulsive disorder (OCD) are reported. The OCD was manifested by repetitive, stereotyped, complex, egodystonic behaviors that were disabling. These cases and other neurological syndromes with OCD (Gilles de la Tourette syndrome, neuroacanthocytosis, postencephalitic parkinsonism, caudate infarction, carbon monoxide poisoning, manganese intoxication, anoxia, progressive supranuclear palsy, Sydenham's chorea, and frontal lobe lesions) indicate that the frontal lobe, caudate nucleus, and globus pallidus are members of a complex circuit that plays a key role in mediating the symptoms of OCD. Evidence of excitatory subcortical output to cortex is shared by many neurological disorders manifesting OCD.

Basal Ganglia↗
PubMed1992

Cefuroxime and cefuroxime axetil versus amoxicillin plus clavulanic acid in the treatment of lower respiratory tract infections.

In a large multinational study, the clinical and bacteriological efficacy of intravenous cefuroxime 750 mg t.i.d. followed by oral cefuroxime axetil 500 mg b.i.d. was compared to that of amoxicillin plus clavulanic acid (CA) administered as 1.2 g intravenously t.i.d. followed by 625 mg orally t.i.d. in the treatment of lower respiratory tract infections in hospitalised patients. A total of 512 patients were entered (256 in each treatment group). All were suffering from pneumonia or acute exacerbations of chronic bronchitis or bronchiectasis and required initial parenteral antibiotic therapy. Parenteral therapy lasted 48 to 72 h and was followed by five days of oral therapy. The clinical responses in the two treatment groups were very similar: 223 of 256 (87.1%) patients were cured or improved with cefuroxime/cefuroxime axetil compared to 220 of 256 (85.9%) with amoxicillin/CA. Positive pre-treatment sputum samples were obtained from 44% of the patients. Clearance rates obtained were again similar: 72.8% with cefuroxime/cefuroxime axetil and 70% with amoxicillin/CA. Ten percent of the isolates were beta-lactamase producers, similar numbers of which were cleared in both groups. Both regimens were generally well tolerated, with only 5% of patients treated with the cefuroxime regimen and 4.3% of patients treated with amoxicillin/CA experiencing drug-related adverse events. Cefuroxime/cefuroxime axetil "follow-on" therapy produces clinical and bacteriological efficacy equivalent to that of amoxicillin/CA, with the advantage of twice daily oral administration.

Administration, Oral↗
PubMed1991

TGF beta elicits opposite responses in clonal subpopulations of NRK-49F cells.

Clonal subpopulations of NRK-49F cells were isolated and characterized for their responses to transforming growth factor beta (TGF beta). Two fibroblastic clones, N1 and N4, were found to have opposite TGF beta responses. TGF beta inhibits EGF-induced proliferation in growth-arrested, subconfluent monolayer cultures of N1 but not N4 cells. In contrast, TGF beta stimulates DNA synthesis and an increase in cell number in N4 but not N1 cells. The inhibitory effect of TGF beta on DNA synthesis in N1 cells is due not to modulation of the EGF receptor or other early G1 events. EGF-induced myc mRNA accumulation is not inhibited, and the action point for TGF beta inhibition of the entry into S of N1 cells is at the G1-S boundary.

Animals↗
PubMed1991

Antibacterial activity and inhibition of protein synthesis in Escherichia coli by antisense DNA analogs.

Protein synthesis, which takes place within ribosomes, is essential for the survival of any living organism. Ribosomes are composed of both proteins and RNA. Specific interaction between the 3' end CCUCC sequence of prokaryotic 16S rRNA and a partially complementary sequence preceding the initiating codon of mRNA is believed to be a prerequisite for initiation of protein synthesis. Here we report the use of short (three to six nucleotides) synthetic DNA analogs complementary to this sequence to block protein synthesis in vitro and in vivo in Escherichia coli. In the DNA analogs the normal phosphodiester bond in the antisense DNA was replaced by methylcarbamate internucleoside linkages to enhance transport across plasma membranes. Of the analogs tested, those with the sequence AGG and GGA inhibit protein synthesis and colony formation by E. coli strains lacking an outer cell wall. Polyethylene glycol 1000 (PEG 1000) was attached to the 5' end of some of the test methylcarbamate DNAs to enhance solubility. Analogs of AGG and GGAG with PEG 1000 attached inhibited colony formation in normal E. coli. These analogs may be useful food additives to control bacterial spoilage and biomedically as antibiotics.

3T3 Cells↗
PubMed1990

Nutrient intakes in long-stay mentally handicapped persons.

A study of the dietary intake of 115 male and 217 female mentally handicapped persons aged 15-64 years in five long-stay institutions was carried out using a semi-weighed technique over 4 d. Nineteen per cent of males and 5% of females were classified as being underweight and 15% of males and 27% of females were classified as being obese. The average daily intakes of nutrients were: energy 8.8 MJ, protein 92 g, carbohydrate 218 g, fat 101 g, dietary fibre 18 g, calcium 1024 mg, iron 12.5 mg, vitamin B6 1.4 mg, vitamin B12 10.8 micrograms, ascorbic acid 68 mg. The distribution of energy between protein, carbohydrate and fat was 18, 39 and 43% respectively. Energy intakes were not related to ambulatory status, degree of mental handicap, the level of drug usage or body mass index. Energy intakes varied significantly between hospitals and between the sexes.

Adolescent↗
PubMed1990

Subcutaneous fat necrosis with hypercalcemia.

We report the case of an infant with diffuse subcutaneous fat necrosis following birth asphyxia who had hypercalcemia and the rare complication of venous calcification. The clinical and radiologic findings resolved over 5 months. The disease is characterized by the presence of painless subcutaneous nodules, mainly over bony prominences, possibly associated with hypercalcemia and calcification. Early identification of hypercalcemia will avert its serious sequelae.

Calcinosis↗