Biomedical subjects
Publications and source records attributed to E Cunningham.
A rapid-access but limited vocabulary communication aid for the non-vocal and speech impaired is useful in some well defined situations. The design and construction of such a device is described. Three distinct situations have been identified where an aid is essential and an initial evaluation has shown the Pocket Speech Aid to be very successful.
Inhibitors of DNA gyrase in Escherichia coli exerted differential effects on the genetic transformation of Neisseria gonorrhoeae. When competent cells of the gonococcus were exposed to novobiocin before the uptake of transforming antibiotic resistance DNA, there was a 50 to 60% reduction in the number of transformants compared with the number of control untreated cells. Norfloxacin, a more potent inhibitor of DNA gyrase and an analog of nalidixic acid, nearly abolished the production of transformants by recipient cells. On the contrary, exposure of competent cells to nalidixic acid had no effect on transformant yield. The target of these inhibitors appears to be at the level of recombination. Possible mechanisms are discussed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The familial association of pulmonary stenosis, atrial septal defect, and unique electrocardiographic abnormalities involving a mother and two children is reported. Familial pulmonary stenosis not occurring as part of a named syndrome or without associated multiple congenital abnormalities is rare. The constellation of pulmonary stenosis, atrial septal defect, and the particular electrocardiogram abnormalities present here is to our knowledge previously unreported. The pattern of inheritance is consistent with an autosomal dominant mode of transmission.
The renal handling of Ca in response to Na intake was evaluated in 12 patients with hypercalciuria and active kidney stone disease. There was no depression of urinary Ca excretion in response to the hypocalciuric effect of metolazone. Patients were hospitalized and their Ca and Na excretions measured while on a 190-mEq Na, 800-mg Ca, 1200-mg PO4- diet. These measurements were then repeated after Na intake decreased to 35 mEq/day while other variables, including diuretic dose and Ca intake, were unchanged. Two distinct responses were elicited by patients after Na restriction. In group I or the "responders" (n = 4), Ca excretion was reduced from 255 +/- 31 to 62 +/- 6 mg/24 hr. In the control group (n = 4), Ca excretion decreased from 95 +/- 8 to 57 +/- 11 mg/24 hr at similar levels of Na excretion. In group II or the "nonresponders" (n = 8), Ca excretion fell from 317 +/- 31 to 154 +/- 17 mg/24 hr when Na excretion was less than 50 mEq/24 hr. Metolazone with Na restriction normalized urine Ca excretion to the same order as in control subjects in group I. This is indicative of a mild Ca leak or a salt-sensitive leak. Despite diuretic and Na restriction most of the patients with hypercalciuria (group II) did not reabsorb Ca in a normal manner. This is indicative of a severe reabsorptive defect for Ca despite normal Na handling.
The relationship between norepinephrine (NE) and prostaglandins in the regulation of systemic blood pressure during pregnancy was examined in conscious rabbits. The arterial prostaglandin E2 (PGE2) concentration was higher in pregnant than in nonpregnant rabbits. Resting blood pressure was slightly lower in the gravid animals. The pressor response to incremental doses of intravenous NE was blunted in the pregnant rabbits. Meclofenamate, a cyclooxygenase inhibitor, failed to alter the resting blood pressure in either group of animals, although it reduced PGE2 levels more than 60% in the pregnant rabbits. The pressor response to NE was significantly increased only in the pregnant rabbits when the NE infusion was repeated following meclofenamate. Pregnant rabbits could also be differentiated from nonpregnant by their higher peripheral blood levels of NE and their uniform hypotensive response to alpha-adrenergic blockade. These observations define an altered responsiveness to both endogenous and exogenous NE in pregnant rabbits that appears to be related to an increase in vasodilator prostaglandins.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Metolazone, a nonthiazide diuretic with the hypocalciuric effect of the thiazides, was evaluated in patients with idiopathic calcium nephrolithiasis. During the mean 3-yr treatment period, there was a 77% decrease in stone incidence in 38 male patients (from 2.10 to 0.49 stones/patient/year). Urine calcium decreased 51% (from 231 +/- 19 to 114 +/- 7 mg/24 hr after 13 mo therapy). The treatment response was the same when these patients were divided into normocalciuric (n = 23), borderline hypercalciuric (n = 10), and hypercalciuric groups (n = 5). In six other patients with high sodium intake there was no decrease in urine calcium on stone formers regardless of the initial level of urine calcium excretion. High sodium intake may blunt and low intake potentiate the hypocalciuric effect of metolazone.
Acute myoglobinuric renal failure developed in three patients during the course of influenza virus infection. Muscle enzyme levels were elevated in all patients. Myoglobin was detected in the urine or serum by immunodiffusion. Recent influenza infection was documented by elevated hemagglutination inhibition titers. One patient died, whereas the remaining two patients completely recovered renal function. These patients with influenza infection represented more than half of the cases of myoglobinuric renal failure seen on the medical services of the study institutions during ths same period. These observations suggest that the association between influenza infection and myoglobinuric renal failure may be more common than previously suspected.
A 14-year-old boy initially had severe hemoptysis and a coin lesion in the left lower lobe on the chest x-ray film. Pulmonary arteriographic studies suggested the presence of a pulmonary varix. Pathologic examination of the specimen obtained at surgery revealed a bronchogenic cyst. Pulmonary varices are extremely rare. Bronchogenic cysts must be included in the differential diagnosis of these lesions.
A patient with systemic lupus erythematosus (SLE), followed up over a six-month period, exhibited numerous immunologic abnormalities and varied renal pathologic features. Initial findings included minimal glomerular lesions, serum antibodies directed solely against nuclear RNA protein, and lupus band test showing pure IgM deposition. These findings suggested a good prognosis. Subsequently, the patient developed acute renal failure secondary to an interstitial lupus nephritis, without progression of the glomerular abnormality. Serum antibodies to the nuclear non-nucleic acid macromolecule and single stranded and native DNA were demonstrated concurrently. New skin deposits of IgG and IgA in addition to IgM also were observed. This patient demonstrates the potential progression of lupus renal disease despite the initial favorable prognostic indicators.
The histories of the persons dying in a country district during 1973 were examined. The number of visits to the doctors, and also the days spent in hospital by their close relatives in the two years before 1973 were compared with those in the two years that followed. A control group was also examined. There were significant differences in these figures. Analysis suggests that ill health in those aged 50 and over increases after the death of a close relative. A group which is "at risk" after bereavement appears to have been identified.
Procaineamide is now available as a sustained-release preparation. This preparation was administered in an eight-hourly regime to 26 patients, and therapeutic blood levels were obtained for the duration of the 56-hour study period in 20 patients. No side effects were observed. Inadequate blood levels may be predicted from a single blood level eight hours after the first dose, which could allow for dosage adjustment.
Explore the source record for details and available documents.
The cystatin family of proteins exists in both excreted and intracellular forms, and appears to be involved in protective and regulatory roles, inhibiting a variety of bacterial, viral and intracellular proteases. The amino acid sequences of several human forms of cystatin are known, but currently only the structure of chicken cystatin (approx. 40% homologous to the human forms) has been experimentally determined. The objective of this study was to use the X-ray coordinates of chicken cystatin to construct computer models of the structures of three human salivary forms (SN, S and SA). These structures were energy-minimized and subjected to dynamic simulations. The resultant structures were compared to determine conformational differences. Global root mean square deviations between equivalent atoms ranged from 1.4 A to 3.9 A. The closest structural similarity to chicken cystatin involved cystatin SN, which also showed the highest (68%) functional sequence homology. Local secondary structure was examined in more detail. In comparisons of alpha-carbon position the third beta-strand (77% functional sequence conservation) and its preceding loop (60% conserved) showed the highest structural conservation in S, while beta-strand 4 showed the highest structural conservation in SN and SA. Throughout their structures, SN and SA were more structurally similar to chicken cystatin than to salivary cystatin S. There are two regions of conserved, negatively charged residues in the salivary cystatins, which appear to be spaced so that they are capable of interaction with hydroxypatite. It is concluded that not only does structural modelling by analogy provide detailed models of salivary cystatins that can be tested by future experimentation, but also that examination of the models has revealed potential sites of interaction with hydroxyapatite.
A portable, battery-powered communication aid with speech output, which can be operated by patients with limited finger control, is described. The device is sufficiently versatile to try out different methods of selection of words or phrases in the search for an acceptable, portable communication aid for the speech impaired.