Effect of naloxone on the haemodynamics and the outcome of experimental acute pancreatitis in dogs

Endogenous opioid peptides may play a role in the genesis of pancreatic damage in acute pancreatitis. The effects of naloxone on the haemodynamic changes in acute pancreatitis were investigated by inducing it in dogs with pancreatic ductal injection of fresh trypsin-bile mixture. In the control group (n = 8), acute pancreatitis was characterized haemodynamically by falls in the maximum positive and negative dP/dt (+/- dP/dt), cardiac output (CO) and cardiac index (CI), and increases in the pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) as well as an early reduction of pancreatic blood flow (PBF). In another set of eight dogs (naloxone group), naloxone was given intravenously 10 min after the induction of acute pancreatitis (80 micrograms/kg as a bolus + 80 micrograms/kg/h for 3 h). Compared with untreated dogs, naloxone significantly increased PBF and the +/- dP/dtmax; prevented the significant decreases in CO and CI and increases in PVR and SVR, and reduced significantly the severity of pancreatitis, as assessed by both the histological staging and the mortality rate. These results suggest that naloxone limits the progression of acute pancreatitis from oedematous to haemorrhagic form. It is proposed that endogenous opioid peptides may play a role in the pathophysiology of acute pancreatitis.

Fluid shear stress modulates cytosolic free calcium in vascular endothelial cells

Cytosolic free Ca2+ concentration ([Ca2+]i) was monitored in single and groups of fura-2-loaded bovine aortic endothelial cells (BAEC) during exposure to laminar fluid shear stress. Application of a step increase in shear stress from 0.08 to 8 dyn/cm2 to confluent BAEC monolayers resulted in a transient increase in [Ca2+]i, which attained a peak value in 15-40 s, followed by a decline to baseline within 40-80 s. The magnitude of the [Ca2+]i responses increased with applied shear stress over the range of 0.2-4 dyn/cm2 and reached a maximum at greater than 4 dyn/cm2. Transient oscillations in [Ca2+]i with gradually diminishing amplitude were observed in individual cells subjected to continuous high shear stress. Elimination of extracellular Ca2+ with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, blockade of Ca2+ entry with lanthanum, depolarization of the cell membrane with high K+, and preconditioning of BAEC in steady laminar flow had little effect on the [Ca2+]i response. In the presence of ATP or ADP, application of shear stress caused repetitive oscillations in [Ca2+]i in single BAEC, whose frequency was dependent on both agonist concentration and the magnitude of applied shear stress. However, apyrase, an ATPase and ADPase, did not inhibit the shear-induced [Ca2+]i responses in standard medium (no added ATP or ADP), suggesting that the shear-induced [Ca2+]i response is not due to ATP released by endothelial cells.

Epidermal growth factor-induced survival and proliferation of neuronal precursor cells from embryonic rat mesencephalon

Neuronal and glial precursor cells were isolated from primary cultures of embryonic rat mesencephalon. The separation of precursor cells from the neurons was accomplished by the resuspension of the primary cells by trypsinization, followed by replating. This procedure resulted in the death of differentiated neurons and the survival of precursor cells. The survival and proliferation of the replated precursor cells required the presence of epidermal growth factor (EGF) in the culture medium. The precursor cells differentiated into neurons and astrocytes, as determined by immunocytochemical staining with antibodies to neuron specific enolase (NSE) and tau protein or glial fibrillary acidic protein (GFAP) respectively.

Is age an independent predictor of early and late mortality in patients with acute myocardial infarction?

PURPOSE

To determine whether advancing age is an independent predictor of increased mortality following acute myocardial infarction or simply a marker for more extensive cardiac disease, a higher prevalence of comorbid conditions, and/or differences in therapeutic approach.

PATIENTS

A total of 261 consecutive patients with documented acute myocardial infarction admitted to a university teaching hospital during a 1-year interval.

METHODS

Seventy-four variables were analyzed to determine univariate predictors of inhospital and 1-year post-discharge mortality. Multiple linear regression models were constructed to determine independent predictors of early and late mortality after adjusting for baseline and therapeutic differences between younger and older patients.

RESULTS

Compared with patients less than 70 years (n = 124), patients greater than or equal to 70 years (n = 137) were more likely (all p less than 0.05) to be female and have a prior history of ischemic heart disease. New York Heart Association functional class and Killip class on admission were higher in older patients, as were the admission serum creatinine and blood urea nitrogen levels. Serum albumin and peak creatine kinase levels were lower in older patients, but older patients were more likely to exhibit left ventricular hypertrophy or atrioventricular block on the initial electrocardiogram. Finally, younger patients were three times as likely to receive a thrombolytic agent and 66% more likely to receive intravenous beta-blockade than older patients, and younger patients were also more likely to receive heparin and intravenous nitroglycerin. Hospital mortality was 5.6% in patients less than 70 years versus 16.1% in patients greater than or equal to 70 years (p = 0.013). After adjusting for baseline and therapeutic differences, independent predictors of hospital mortality were systolic blood pressure on admission (inverse correlation, p = 0.0095), beta-blocker therapy (inverse correlation, p = 0.01), age (p = 0.014), peak creatine kinase level (p = 0.015), and Killip class (p = 0.035). Among hospital survivors, 1-year post discharge mortality was 6.8% in patients less than 70 years versus 19.1% in those greater than or equal to 70 years (p = 0.001). Independent predictors of post-discharge mortality after adjusting for age-related baseline and therapeutic differences were admission heart rate (p = 0.0004), age (p = 0.011), left ventricular ejection fraction (inverse correlation, p = 0.012), initial non-Q-wave myocardial infarction (p = 0.026), and the blood urea nitrogen level (p = 0.036).

CONCLUSION

After adjusting for multiple baseline and therapeutic differences between older and younger patients, age per se remains a strong independent predictor of both inhospital and 1-year post-discharge mortality rates in patients with acute myocardial infarction.

Analysis of urban-rural population dynamics for China

The multiregional demography approach is used in an analysis of the urban—rural population dynamics of China. Multiregional population-accounts and methods of estimation of demographic rates are developed on the basis of the multiregional population-accounts concept. An accounts-based urban—rural population projection model is established and used to project the population of China from 1988 to 2087.

Model representation of salicylate pharmacokinetics using unbound plasma salicylate concentrations and metabolite urinary excretion rates following a single oral dose

The pharmacokinetics of salicylic acid (SA) and its metabolites have been studied in 5 volunteers after administration of 3 g salicylic acid (as sodium salicylate) and collection of serial samples of blood and urine. SA and its metabolites were assayed with a HPLC method specific for each species. The urinary excretion rates of individual metabolites were analyzed using unbound plasma SA concentrations and Lineweaver-Burke plots. The analysis confirmed that the formation of SA urate (SU) and SA phenolic glucuronide (SPG) metabolites are saturable processes, and showed that the Michaelis-Menten values derived are consistent with earlier estimates derived solely from urinary data. The unbound salicylate plasma concentration-time profiles were then analyzed with various models assuming either saturable clearances for metabolite formation and/or saturable protein binding. The data were best described with a model that included both saturable protein binding and saturable metabolism. The model assumed first-order absorption kinetics and instantaneous distribution into extravascular and tissue compartments. The model was validated by comparing predicted relationships between the apparent volume of distribution, clearance, and plasma salicylate concentrations with previous relationships obtained using steady state data.

[Effects of verapamil on prostacyclin, thromboxane and pancreatic blood flow of rats with experimental acute pancreatitis]

We studied the effects of the calcium channel blocker, verapamil on experimental acute pancreatitis (AP) in rats. The pancreatic blood flow (PBF) and pancreatic tissue perfusion (PTP) were measured after induction of AP. At the same time, the plasma levels of TXB2 and 6-keto-PGF1 alpha were determined by radioimmunoassay. The survival rate and the mean survival time after induction of AP were determined and the pancreatic histology was examined by light and electron microscopy. The results demonstrated a significant early fall in PBF and PTP, a marked increase in TXB2 levels and a slight increase in 6-keto-PGF1 alpha after induction of AP. Treatment with 0.1 mg/100 g verapamil significantly increased PBF and PTP, and decreased TXB2, resulting in a normalization of TXB2/6-keto-PGF1 alpha ratio. The treated animals also exhibited significant increase in the survival rate and the survival time. They also showed decrease in the severity of pancreatic hemorrhage and necrosis, and in the damage to the cellular ultrastructures. These data suggest that calcium blockade increases PBF and PTP, limits the prostanoid imbalance in the early phase of AP, and may influence the development of experimental acute pancreatitis in rats.

[Clinical value of the Chengdu classification of non-Hodgkin's lymphomas]

Two hundred forty-nine cases of non-Hodgkin's lymphomas (NHL) were reviewed by using the working classification of NHL (Chengdu, 1985). The results showed that the patients of 249 cases of NHL ranging in age from 5 to 76 years, with the mean age of 42 of the types were separated into three major prognostic groupings as follows: 1. low (41 of 249 cases, small lymphocytic 27 cases, lymphoplasmacytoid 2 cases, follicular cleaved 7 cases, follicular cleaved and noncleaved 5 cases); 2. intermediate (58 of 249 cases, diffuse cleaved 28 cases, diffuse cleaved and noncleaved 27 cases, follicular noncleaved 3 cases); and 3. high grade malignancy (150 of 249 cases, diffuse noncleaved 49 cases, lymphoblastic 41 cases, immunoblastic 13 cases, polymorphic 39 cases, clear cell 2 cases, histiocytic 6 cases). Each group was significantly different from the others (P less than 0.05). The prognosis of patients with angioimmunoblastic lymphadenopathy like T-cell lymphoma (9 of 249 cases) was not more significant (P greater than 0.05) than that of patients with other polymorphic lymphoma (30 of 249 cases). The results showed this Chengdu classification of NHL is good for practice and usage in clinical evaluation and routine surgical pathology.

Photoacoustic study of iron-deficiency anaemia

A photoacoustic spectrum of a smear of whole blood clearly shows all of the details of the haem absorption in an optical spectrum and good optical absorption data without a data extraction procedure. There are three peaks; gamma (420 nm), beta (550 nm), and alpha (585 nm) in the band 350-700 nm. For iron-deficiency anaemia the peak/peak ratios, ratios of the value of peak gamma to that of the peak beta and peak alpha, and the integral/integral ratios, ratios of the value of the integral under the peak gamma to that under the peak beta, peak alpha, peak beta and peak alpha are closely related to the variation of haemoglobin concentration. Linear relationships among the ratios and the Hb concentration are found. These ratios could be a good index of haem synthesis disturbance.

[An application of His bundle electrogram to locate fossa ovalis during percutaneous transseptal balloon valvuloplasty]

A new technique to locate the point of atrial septal puncture, i.e. His bundle electrogram locating method (HBELM), was reported. By using this HBELM, the successful rate of atrial septal puncture was 100% in 21 cases of mitral stenosis during percutaneous transseptal balloon valvuloplasty and in 5 cases of them, the puncture needle got into left atrium smoothly through patent fossa ovalis at the position determined by HBELM without making puncture. As well known, the point of atrial septal puncture is fossa ovalis. According to the anatomy, His bundle is located at the same horizontal line as fossa ovalis. After HBE being recorded, a horizontal line is drawn from the point of His bundle catheter electrode. The authors suggest that the intersect of this line with right border of thoracic vertebra should be the point of atrial septal puncture. The above study showed that HBELM for atrial septal puncture is a correct and easy method and may be better than other methods used before.

[Colo-rectal cancer in the elderly]

From September 1981 to December 1988, fiberoptic colonoscopy was performed in 4595 subjects, among whom 476 colorectal cancers were found. Among 692 subjects with ages beyond sixty, 164 (23.7%) colo-rectal cancers were discovered. This study shows that the median age of colo-rectal cancer has increased by 7 years from 45 of the 1950s to the 1970s. The incidence of cancer of the ascending colon is higher (8.5%) in subjects older than 60. It should be noted that 124 out of 164 (75.6%) patients had been misdiagnosed. With prolonging life expectancy in the Chinese population, we strongly advise fibercolonoscopy for the early detection of colo-rectal cancer in the elderly.

Immunoglobulin G subclass deficiency in children with recurrent respiratory tract infections

With monoclonal antibodies serum immunoglobulin G(IgG) subclasses were measured in seventy children aged 2 to 13 years with recurrent respiratory tract infections including upper respiratory tract infections, otitis media, sinusitis, asthmatic bronchitis and pneumonia. 211 healthy, aged-matched children served as control. IgG subclass deficiency was found in 19 out of the 70 patients (27.1%, single IgG1 deficiency in 7, IgG2 deficiency in 4, combined IgG1-IgG3 deficiency in 5, IgG1-IgG2-IgG3-IgG4 deficiency, IgG1-IgG2-IgG4 deficiency and IgG2-IgG4 deficiency each in 1). The incidence of IgG subclass deficiencies was in the sequence as follows: IgG1, 20%; IgG2, 10%; IgG3, 8.6% and IgG4, 4.3%. The results suggest that IgG subclass deficiency indicate a common disorder in children with recurrent respiratory tract infections.

[The relationship between protection of regenerating rat liver against carbon tetrachloride and change of its mitochondrial respiratory activity]

Protection of regenerating rat liver against carbon tetrachloride (CCl4) poisoning 96 h after partial hepatectomy was observed, and the respiratory activity of its mitochondria was determined by using oxygen electrode method. The results were as follows: (1) Mortality in partial hepatectomized rats (PHR) caused by CCl4 (50%, 10 ml/kg) was reduced significantly as compared with sham operated rats. (2) Following hepatic damage induced by CCl4 (50%, 5 ml/kg), the levels of serum bilirubin and sGPT in PHR were significantly lower than those in sham operated rats. Histological examination of the liver also showed a significant extent of repair. (3) Respiratory activity of regenerating liver mitochondria in PHR with or without CCl4 poisoning was higher than that in sham operated rats, and the respiratory activity went parallel with the degree of repair of histological damage, the reduction of serum bilirubin, sGPT and mortality. The results mentioned above indicate that increase of respiratory activity of regenerating liver mitochondria and resistance to CCl4 may play an important role in the protection of regenerating liver against CCl4.

Study of normal and cancerous urine using photoacoustic spectroscopy

Photoacoustic spectroscopy (PAS) is a valuable technique, increasingly applied in clinical and biological analysis. Light absorption properties of urine and body tissue can be obtained more easily by the PAS technique because of its high sensitivity, than by the conventional optical techniques. By observing their absorption properties it is possible to diagnose some diseases and in this study we have used PAS to assess cancerous changes in urine and tissue. Three groups were studied: normal individuals; patients with cancer; and patients with cancer and subsequent inflammation; and the characteristic light absorption peaks obtained for a certain band (240-420 nm). These results were compared with the clinical diagnosis and proved consistent and reliable for the diagnosis of urinary tract cancer subsequently confirmed by operation. This method will probably be a useful tool for the early clinical diagnosis of cancer of the urinary system.

[The effects of pulsatile pumping on tissue perfusion and renal function during deep hypothermic low flow perfusion]

The effects of pulsatile pumping on tissue perfusion and renal function during deep hypothermic low flow perfusion were compared with non-pulsatile pumping. Twelve dogs were classified into 2 groups by the perfusion technique used. Animals were core cooled to 20 degrees C esophageal temperature with 80 ml/kg/min perfusion rate and maintained at the level for 2 hours with low flow perfusion (LFP) (30 ml/kg/min), then rewarmed to 35 degrees C with 80 ml/kg/min flow rate. As compared with the non-pulsatile group, pulsatile group demonstrated greater urine output during rewarming (p less than 0.05) and greater lymph flow during core cooling (p less than 0.05). The non-pulsatile group showed higher lymph/plasma protein concentration ratio (Lc/Pc) during LFP and rewarming (p less than 0.05), and greater plasma protein clearance during rewarming (p less than 0.05), and much higher increase of interstitial fluid pressure. The lesser water retention during bypass was also noted in the pulsatile group (28.6 +/- 27.6 ml/kg vs 85.4 +/- 52.1 ml/kg, p less than 0.05). These findings have suggested that the pulsatile perfusion may be useful for the infant cardiopulmonary bypass reducing tissue edema and preserving better renal function.