Biomedical subjects
Publications and source records attributed to D Camp.
A 29-week premature infant with severe central hypoventilation secondary to Prader-Willi syndrome required mechanical ventilation until 55 days of age. This disorder must be considered in the differential diagnosis of a premature infant who does not have primary lung disease but has significant hypotonia because the respiratory failure may require prolonged supportive care.
Since its approval by the USFDA in 1998, the LVAD has been used primarily as a bridge to transplantation. It has been effective in improving the overall health and debilitated states in patients with cardiomyopathies and CHF by restoring them to a near normal hemodynamic state and improving end-organ blood flow. Recent studies indicate that the LVAD might be useful as a destination therapy, making transplantation unnecessary, providing one solution to the imbalance of heart donor supply to transplant candidate need.
Tethering the N6-substituents of N6-substituted adenosines to N1 has resulted in a series of conformationally restricted adenosine analogues. The resultant diimidazo[1,2-c:4',5'-e]pyrimidines were shown to be adenosine A1 selective.
Silicon-based microphysiometry, measuring extracellular acidification rate of cells in culture, demonstrated that a series of diimidazo[1,2-c:4',5'-e]pyrimidines were agonists at the human adenosine A1 receptor. 5-amino-7,8-dihydro-3-ribofuranose-8-(R)-(phenyl)-3H-diimidazo [1,2-c:4',5'-e]pyrimidine (2a) had an EC50 of 100 microM and reached 90% of the Emax produced by R-PIA.
The microbial biodegradation of simulated graywater, containing 21.5 mg of linear alkylbenzene sulfonate liter-1, was investigated with a continuous-flow bioreactor with 100% biomass recycle. Low concentrations of organic matter in the ultrafiltration eluate were achieved by hydraulic residence times as short as 1.6 h and for periods of up to 74 days at a hydraulic residence time of 6 h. Upon a shift from the chemostat to the biomass recycle mode, the increase in biomass with time approximated a linear rather than an exponential function. Biomass densities as high as 6.8 g of cell protein liter-1 were reached; this was 50-fold higher than the steady-state biomass level in chemostats fed the same medium. We assessed physiological changes in the microbial community after a switch from the chemostat to the biomass recycle mode. Over 150 h, there was a two- to fourfold decrease in the respiratory potential of the microbes. After this decrease, respiratory potentials were relatively constant up to 74 days of operation. A decline in reactivity was also indicated by increasing lag periods before growth in response to organic nutrient inputs and by a decrease in the proportion of cells able to reduce tetrazolium dye. However, the bioreactor system was still capable of rapidly metabolizing inputs of organic matter, because of the very high biomass concentrations. It appears that < 10% of the organic carbon inputs accumulate as biomass.
Calculations to predict the radiation environment for spacecraft in low earth orbit sometimes ignore the contribution from secondary radiation products. However, the contribution of secondaries, particularly neutrons, on heavy spacecraft or in planetary bodies can be of concern for biological systems. The Shuttle Activation Monitor (SAM) and Cosmic Radiation Effects and Activation Monitor (CREAM) experiments provide valuable data on secondary (as well as primary) radiation effects. Comparisons have been made between induced activity from flight-exposed samples, induced activity in a ground-irradiated sample, and Monte Carlo-derived predictions with and without secondaries. These comparisons show that for a flight-exposed sample, predictions which omit the secondary contribution result in a spectrum that is too low by a factor of 2. The addition of the secondaries results in a predicted spectrum that closely matches the measured data.
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This study takes in account all post operative deaths during the year 1990 in one surgical Professorial unit of Lille academic hospital (France). During this year, 1492 consecutive patients underwent surgery. The mean age of deceased patients was 63.7 years. 15 died after emergency procedure and 12 after elective surgery. Lastly 2 patients died without any operation. The most common condition encountered in those cases was oesophageal carcinoma, thereafter gastric or duodenal complicated peptic ulcer, and finally colonic carcinoma and diverticular disease. 13 patients had neoplasia (45%). From a critical point of view, 14 patients died after surgical indication or procedure of questionable legitimacy. The comparison with a similar study conducted five years ago and the analysis of these charts allow us to reaffirm some basic principles of surgery.
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UNLABELLED: Modified neck dissection (MND) is not recommended for surgery of thyroid carcinoma (TC) in the absence of grossly involved nodes, except for medullary thyroid carcinoma, and clinical node recurrence in uncommon at follow-up (3% for us). But several authors report metastatic cancer in non-palpable nodes up to 70% on MND specimens. The fear of overlooking occult metastatic nodes prompted us to sample even normal appearing nodes and to rely on frozen sections (FS) to make a decision whether or not a MND should be done. PATIENTS AND METHODS: 130 among 300 consecutive patients operated for TC were submitted to supraclavicular node sampling with FS. All pathological varieties were covered. In 170 cases, sampling was not done purposely (lack of intraoperative diagnosis of carcinoma: 75) or for other reasons (absence of obvious nodes: 77; unavailable pathologist: 14; miscellaneous: 4). All specimens were reviewed by paraffin sections (PS). RESULTS: Among the 130 patients; 25 had gross metastatic node involvement, confirmed by FS+ and PS+; 1 had grossly equivocal nodes with FS- and PS+; 104 had grossly normal nodes. In 101 (97%) this was confirmed by FS- and PS-. In 3 (3%) FS was +, leading to MND, and PS confirmed metastatic involvement in 2. All 32 specimens of routine node sampling done in 1988 have been reviewed by serial cross sections, one each millimeter (331 sections). One only disclosed one occult metastatic invasion. CONCLUSION: No more than 3% of the grossly normal supraclavicular nodes are metastatic at the time of surgery.(ABSTRACT TRUNCATED AT 250 WORDS)
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In 1985, 1409 consecutive patients underwent surgery in one surgical Professorial Unit of Lille (France). 45 (3.2%) died post-operatively: 28 (62%) were more than 70 years of age, 23 (50%) died after emergency procedure and 18 (40%) died in sepsis. Nothwerthy in retrospect, 20 (44%) died after surgical indication or procedure of questionable legitimacy. Preoperative appraisal of the surgical risk is still challenging nowadays but conclusions drawn from those charts should avoid identical outcome in similar patients.
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Studies were conducted to determine the effects of hypoxemia on cerebral blood flow and the influence of hyperoxia and hypoxemia on autoregulation of cerebral blood flow in the unanesthetized newborn dog. Twenty-one newborn dogs less than 2 weeks of age were studied. Cerebral blood flow was measured using radioactive microspheres during successive periods of normotension, hypotension (produced by blood withdrawal) and normotension (produced by infusion of previously withdrawn blood). In the hyperoxic animals, arterial pO2 was maintained above 250 torr by having the animal breathe 100% oxygen, while in the hypoxemic animals arterial pO2 was maintained between 30 and 35 torr by having the animal breathe 12% O2. Cerebral blood flow increased significantly with hypoxemia. In both hypoxemic and hyperoxic animals cerebral blood flow was maintained constant in spite of a large fall in arterial blood pressure and cardiac output, demonstrating the presence of autoregulation. Calculated oxygen transport to the brain was constant during hypoxemia and hypotension in all animals. Thus autoregulation of cerebral blood flow is present in newborn animals and is preserved under conditions of moderate hypoxemia.