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T Monclair

Publications and source records attributed to T Monclair.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Hernia and testicular retention in children--which condition should be treated and when?].

Children, and also infants, with groin hernias should be operated as soon as the diagnosis is made. Umbilical hernia, on the other hands, does nearly always heal spontaneously, and operative treatment is rarely indicated. The boy with undescended testicles may perhaps be served best if orchiopexy is performed at two years of age. However, it should be emphasized that it has not yet been proved that this approach is superior to a somewhat later performed operation.

Age Factors↗
PubMed1980

Renal bicarbonate reabsorption during bicarbonate loading.

To examine bicarbonate reabsorption at different GFR's, we varied the renal perfusion pressure in anesthetized dogs after inhibiting autoregulation by expanding extracellular volume and infusing ethacrynic acid. At a plasma bicarbonate concentration (PHCO3) of 28 +/- 1 mM, bicarbonate reabsorption varied in proportion to GFR (glomerulotubular balance). When PHCO3 was raised to 52 +/- 2 mM at constant PCO2 and hematocrit, bicarbonate reabsorption was reduced at all levels of filtered load. When plotted against GFR, different results were obtained dependent on the GFR level examined. At the control GFR,. bicarbonate loading reduced bicarbonate reabsorption by 30 +/- 5%. At a GFR level about 50% below the control GFR, bicarbonate loading increased reabsorption by about one third because the inhibitory effect of raising PHCO3 and extracellular pH was not sufficient to counteract the stimulatory effect of a higher filtered load. At intermediate levels of GFR, a rise in PHCO3 did not alter bicarbonate reabsorption. The finding that acetazolamide (30 mg/kg of body wt) at high PHCO3 failed to reduce bicarbonate reabsorption supports the hypothesis that the depressive effect of high extracellular pH on bicarbonate reabsorption may be attributed to reduced net tubular hydrogen ion secretion.

Absorption↗
PubMed1980

Oxygen requirement of bicarbonate-dependent sodium reabsorption in the dog kidney.

The ratio between changes in sodium reabsorption and renal oxygen consumption (Na/O2) was measured in anesthetized dogs at high plasma bicarbonate concentration (32 +/- 1 mM); ethacrynic acid was infused continuously to prevent variations in transcellular NaCl reabsorption when sodium reabsorption was altered by varying plasma PCO2 and glomerular filtration rate (GFR). At high plasma PCO2 (110 mmHg) sodium reabsorption varied in proportion to GRF between 50 and 125% of control GFR (glomerulotubular balance). By reducing PCO2 to 20 mmHg, sodium reabsorption was reduced by 50-60% at constant GFR. The Na/O2 ratio was not significantly different during the two procedures and averaged 48 +/- 2. The ratio between changes in NaHCO3 reabsorption and oxygen consumption averaged 17 +/- 1, which is not significantly different from the Na/O2 ratio of Na-K-ATPase-dependent sodium transport. We propose that NaHCO3 is admitted to the cell by Na+/H+ exchange and that sodium is actively transported by Na-K-ATPase across the peritubular cell membrane; NaHCO3 provides the osmotic force for paracellular reabsorption of water and NaCl (bicarbonate-dependent reabsorption) without additional energy requirement.

Absorption↗
PubMed1979

Renal metabolic rate during changes in bicarbonate-dependent sodium reabsorption in the proximal tubules.

Previous studies indicate that water and at least 2 mol NaCl are reabsorbed in the proximal tubules for each mol NaHCO3 reabsorbed. To examine the effect on cortical energy metabolism of variations in this bicarbonate-dependent sodium reabsorption, the cortical metabolic rate was examined in anaesthetized dogs by the heat production technique during continuous infusion of saline and ethacrynic acid. Sodium reabsorption was altered either by intravenous infusion of a large dose of acetazolamide (500 mg/kg body wt) or by changing plasma Pco2 during metabolic alkalosis. Acetazolamide reduced bicarbonate reabsorption by 71 +/- 2%, sodium reabsorption by 54 +/- 2% and cortical heat production by 21 +/- 3%. A rise in Pco2 to 16.4 +/- 1.3 kPa during metabolic alkalosis increased sodium reabsorption by 25 +/- 3% and cortical heat production by 14 +/- 2%. A similar elevation of plasma Pco2 during metabolic acidosis had no effect on electrolyte reabsorption or the cortical metabolic rate. A reduction in Pco2 to 2.3 +/- 0.3 kPa reduced sodium reabsorption by 40 +/- 3% and cortical heat production by 19 +/- 2%. We conclude that a rise in proximal tubular reabsorption requires energy. However, the changes in energy requirement are small, accounting for previous failures to observe significant changes in cortical energy metabolism during less extensive changes of sodium reabsorption in the proximal tubules.

Acetazolamide↗
PubMed1979

Coupling of NaHCO3 and NaCl reabsorption in dog kidneys during changes in plasma PCO2.

To study the relationship between proximal tubular reabsorption of bicarbonate, sodium, and chloride, the effects of changes in plasma PCO2 were examined in anesthetized dogs. Distal tubular reabsorption was inhibited by ethacrynic acid; plasma bicarbonate concentration was kept constant at 33.4 +/- 0.3 mM; glomerular filtration rate (GFR) was varied over a wide range to examine glomerulotubular balance (constant fractional reabsorption). Hypercapnia (PCO2, 112.0 +/- 2.5 mmHg) increased bicarbonate reabsorption by about 30%, and hypocapnia (PCO2, 19.8 +/- 0.6 mmHg) decreased reabsorption of bicarbonate by more than 50% and altered reabsorption of sodium, chloride, and bicarbonate in the molar ratios 2.7:1.6:1, respectively. During hypercapnia the range of glomerulotubular balance was extended to a GFR 125% of control. During hypocapnia glomerulotubular balance was present only at GFR below 50% of control; reabsorption of bicarbonate sodium, and chloride was constant at GFR exceeding 50% of control. During metabolic acidosis hypercapnia had no significant effect on reabsorption of bicarbonate, sodium, and chloride. These observations support the hypothesis that bicarbonate reabsorption is the main driving force for osmotic reabsorption of water and NaCl in the proximal tubules.

Acidosis↗
PubMed1978

Factors limiting renal proximal tubular reabsorption at high glomerular filtration rate.

To examine the factors limiting proximal reabsorption, distal reabsorption was inhibited by continuous infusion of ethacrynic acid in anaesthetized dogs. During combined infusion of ethacrynic acid and 0.9% saline, autoregulation of renal blood flow is impaired and glomerular filtration rate (GFR) can be varied by lowering or raising renal perfusion pressure. During lowering of GFR reabsorption of bicarbonate, chloride and sodium varied in proportion to reduction in GFR (glomerulotubular balance), but during elevation of GFR the increase in the filtered load of all three ions was excreted and a maximal rate of reabsorption was approached. Administration of acetazolamide reduced the reabsorption of bicarbonate, chloride and sodium in the ratio 1:2:3, whether GFR was at control, reduced (74% of control) or increased (124% of control). Renal blood flow was 80--90% greater at high than at low GFR. These observations indicate that bicarbonate concentration increases along the proximal tubules during elevation of GFR, until plasma bicarbonate concentration is approached at the distal end of the proximal tubules. From then on, bicarbonate reabsorption cannot be further raised by increasing GFR. Proximal tubular sodium reabsoption reaches a maximum at high GFR because NaCl reabsorption varies in proportion to bicarbonate reabsorption.

Acetazolamide↗
PubMed1978

Functional differences of ouabain and ethacrynic acid on renal potassium metabolism in dogs.

Current concepts provide inadequate explanations for the effects of ethacrynic acid (ECA) and ouabain (OUA) on renal potassium metabolism because neither the site of action, nor the tubular effects have been agrreed upon. In the present study on anaesthetized dogs, in vivo inhibitory effects of ECA on mitochondria or Na-K-ATPase were excluded. Firstly, ECA hardly reduced outer medullary metabolic rates in kidneys exposed to OUA and 2,4-dinitrophenol. Secondly, whereas OUA reduced renal Na-KATPase activity by 78% and induced parenchymal potassium release into the renal vein, none of these effects were observed during injection of ECA. During free flow, sodium reabsorption was equally reduced by the two drugs, but fractional potassium excretion was 0.54 +/-0.04 after OUA and 0.99 +/-0.02 after ECA. OUA alone or combined with ECA inhibited almost all ion transport in the distal 60% of the tubular volume as revealed by stop-flow. During ECA alone, chloride reabsorption was reduced more than sodium reabsorption because sodium was exchanged for potassium. ECA and SO4(2-) infusion produced similar stop-flow patterns. Thus, OUA is bound to Na-K-ATPases functionally located to the peritubular cell membrane. ECA promotes potassium secretion probably by inhibiting cellular anion entry at the luminal membrane.

Adenosine Triphosphatases↗
PubMed1978

Characteristics of transcellular NaCl reabsorption in the kidney.

To examine the characteristics of transcellular, energy-requiring NaCl reabsorption, increased delivery of tubular fluid of different bicarbonate and chloride composition to the outer medulla was achieved by infusion of acetazolamide (30 mg/kg body wt) or 0.9% NaCl in anaesthetized dogs. As an index of energy-requiring NaCltransport, cortical and outer medullary metabolism were determined by the heat production technique. Outer medullary metabolism was correlated to sodium excretion but not to chloride excretion. A rise in sodium excretion up to 20-25% of the filtered load during hydropenia was associated with a 70-80% increase in outer medullary metabolism. Further increments in sodium excretion induced by increasing systemic blood pressure and thereby increasing glomerular filtration rate or by infusing 2.9% NaCl did not significantly increase either reabsorption of sodium or cortical and outer medullary metabolism. By infusion of furosemide (2mg/kg body wt) sodium reabsorption and outer medullary heat production could be reduced below control values. These experiments show that sodium rather than chloride determine transcellular NaCl reabsorption. The maximal capacity of this reabsorption system is approached first at sodium excretion rates beyond the physiological range. Calculations based on clearance studies and heat production measurements, before and after furosemide infusion, indicate that transcellular NaCl reabsorption accounts for more than half of the NaCl reabsorption in the kidney.

Acetazolamide↗
PubMed1978

Total body suspension in the treatment of burns. Report of two cases.

Total body suspension by skeletal traction was used in the treatment of two children with severe circular truncal burns. The authors do not know of any previous reports on complete body suspension, and the demonstration of the possible treatment of burn injuries in this way is considered important. The favourable aspects of the treatment, i.e. prevention of infection and pressure sores, easier nursing, physiotherapy and handling during operations, are emphasized.

Baths↗
PubMed1976

Pancreatic metabolic rate measured in vivo with heat-accumulation technique.

This study is the first attempt to apply the heat-accumulation technique for metabolic studies to the pancreas. The initial temperature rise during arterial occlusion was measured with thermocouples sutured into the pancreas of seven anaesthetized pigs. Temperature recording were obtained during alterations of the metabolism induced by infusions of 2,4-dinitrophenol (DNP) and sodium cyanide (NaCN) into the pancreatic head. DNP 2.0 mg/min almost doubled, and NaCN 0.6 mg/min reduced the heat accumulation rate to one half of control. In four pigs the metabolism was estimated by measurements of oxygen consumption in an isolated in situ preparation of the pancreatic head. Median metabolic rate in the unstimulated gland was 0.09 cal/cm3-min. Metabolic rate estimated by heat-accumulation technique in a similar situation was 0.11 cal/cm3-min. The method is considered useful for evaluation of relative variations of pancreatic metabolism.

Animals↗
PubMed1975

Gastric retention following antrectomy and gastroduodenal anastomosis combined with truncal vagotomy.

A clinical series of 208 patients who had elective operations for gastroduodenal ulcer in Surgical Department II, Oslo City Hospital, has been reviewed. The study concentrates on postoperative gastric retention, comparing the frequency of this complication following antrectomy and gastroduodenal anastomosis with and without vagotomy. The patients in the nonvagotomy group had no retention problem. In the vagotomy group, 19 patients (35%) of 54 operated had troublesome postoperative retention. 7 patients (13%) had to have a further operation for this complication, all within 1 year. We no longer use the combined operation as a routine procedure for duodenal ulcer.

Duodenal Ulcer↗