Sodium induces hypertrophy of cultured myocardial myoblasts and vascular smooth muscle cells.

The mechanisms of sodium-induced myocardial hypertrophy and vascular hypertrophy are poorly understood. We tested the hypothesis that a high sodium concentration can directly induce cellular hypertrophy. Neonatal rat myocardial myoblasts (MMbs) and vascular smooth muscle cells (VSMCs) were cultured in a 50:50 mixture of DMEM and M199 supplemented with 10% fetal bovine serum. When the monolayers reached approximately 80% confluence, normal sodium medium (146 mmol/L) was replaced with high sodium media (152 mmol/L, 160 mmol/L, and 182 mmol/L) for up to 5 days. Increasing sodium from a baseline concentration of 146 mmol/L to the higher concentrations for 5 days caused dose-related increases in cell mean diameter, cell volume, and cellular protein content in both MMbs and VSMCs. Increasing the sodium concentration by only 4% (from 146 mmol/L to 152 mmol/L) caused the following respective changes in MMbs and VSMCs: 8.5% and 8.7% increase in cell mean diameter, 27.6% and 27.0% increase in cell volume, and 55.7% and 46.7% increase in cellular protein content. The rate of protein synthesis, expressed as [3H]leucine incorporation, increased by 87% and 99% in MMbs after exposure to 152 mmol/L and 160 mmol/L sodium, respectively, compared with the 146-mmol/L sodium control group. Exposure of MMbs to medium with a sodium concentration of 10% above normal, ie, 160 mmol/L, caused a significant decrease (range, 26% to 44%) in the rate of protein degradation at multiple time points over a 48-hour period compared with normal sodium control cells. The increase in cellular protein content caused by 160 mmol/L sodium returned to normal within 3 days after MMbs were returned to a normal sodium medium. These findings support the hypothesis that sodium has a direct effect to induce cellular hypertrophy and may therefore be an important determinant in causing myocardial and/or vascular hypertrophy in subjects with increased sodium concentration in the extracellular fluid.

Stereotactic radiosurgery as an adjunct to surgery and external beam radiotherapy in the treatment of patients with malignant gliomas.

PURPOSE: To evaluate the efficacy and toxicity of a stereotactic radiosurgery boost as part of the primary management of a minimally selected population of patients with malignant gliomas. METHODS AND MATERIALS: Between June, 1991 and January, 1994 a stereotactic radiosurgery boost was given to 30 patients after completion of fractionated external beam radiotherapy. The study population consisted of 22 males and 8 females, with a range in age at treatment from 5 to 74 years (median: 54 years). Tumor volume ranged from 2.1 to 115.5 cubic centimeters (cc) (median: 24 cc). Histology included 17 with glioblastoma multiforme, 10 with anaplastic astrocytoma, 1 with a mixed anaplastic astrocytoma-oligodendroglioma, and 2 with a gliosarcoma. A complete resection was performed in 9 (30%) patients, while 18 (60%) underwent a subtotal resection, and 3 (10%) received a biopsy only. Fractionated radiation dose ranged from 44 to 62 Gy, with a median of 59.4 Gy. Prescribed stereotactic radiosurgery dose ranged from 0.5 to 18 Gy (median: 10 Gy), and the volume receiving the prescription dose ranged from 2.1 to 158.7 cc (median: 46 cc). The volume of tumor receiving the prescription dose ranged from 70-100% (median: 100%). One to four (median: 2) isocenters were used, and collimator size ranged from 12.5 to 50 mm (median size: 32.5 mm). The median minimum stereotactic radiosurgery dose was 70% of the prescription dose and the median maximum dose was 200% of the prescription dose. RESULTS: With a minimum follow-up of 1 year from radiosurgery, 7 (23%) of the patients are still living and 22 (73%) have died of progressive disease. One patient died of a myocardial infarction 5 months after stereotactic radiosurgery. Follow-up for living patients ranged from 12 to 45 months, with a median of 30 months. The 1- and 2-year disease-specific survival from the date of diagnosis is 57 [95% confidence interval (CI) 39 to 74%] and 25% (95% CI 9 to 41%), respectively (median survival: 13.9 months). No significant acute or late toxicity has been observed. CONCLUSION: Stereotactic radiosurgery provides a safe and feasible technique for dose escalation in the primary management of unselected malignant gliomas. Longer follow-up and a randomized prospective trial is required to more thoroughly evaluate the role of radiosurgery in the primary management of malignant gliomas.

Cellular and vascular responses in acute experimental ocular inflammation.

PURPOSE: To measure simultaneously blood volume, altered vascular permeability, and leukocyte extravasation in ocular inflammation in rabbits at various times and in different anatomic locations after intravitreal endotoxin (lipopolysaccharide [LPS]). METHODS: Nuclides of different emission and decay were used for labeling and then injected intravenously. Ocular blood volumes were measured with technetium 99m, altered vascular permeability with I-125 albumin, and polymorphonuclear leukocyte or mononuclear cell extravasation after labeling with Indium 111. Eyes were divided into anterior eye section, iris-ciliary body, aqueous, and vitreous and posterior eye sections, and measurements were made at 3, 6, 9, 18, and 24 hours after intravitreal LPS injection. Blood volume measurements made it possible to estimate the amount of extravascular protein and the number of extravascular leukocytes. RESULTS: Blood volumes were consistently elevated at all times, usually by approximately 50% and predominantly in the anterior segment. Altered vascular permeability was present at 3 hours, increased at 6 hours, decreased at 9 hours, and was elevated at 18 to 24 hours, predominantly in the anterior eye. Leukocytes in iris-ciliary body appeared in small numbers at 6 hours, increased at 9 hours, and continued to extravasate at 18 and 24 hours. Mononuclear cells were as numerous as polymorphonuclear leukocytes at each time measured. CONCLUSIONS: The quantitation of multiple parameters of ocular inflammation in this experimental model has been helpful in defining when and in what tissue changes occur. Leukocytes are primarily within tissues, particularly in the iris-ciliary body region. Mononuclear leukocytes are a prominent feature at all times and add further support to the concept that the mononuclear phagocyte plays a pivotal role in reactions to LPS.

Hypotensive effect of chronic intrarenal infusion of acetylcholine during angiotensin hypertension.

We examined the role of the pressure natriuresis phenomenon in long-term arterial pressure control. Uninephrectomized dogs were housed in metabolic cages and made hypertensive with a continuous background intravenous infusion of angiotensin II (AngII, 12 ng/kg/min). To increase the ability of the kidney to excrete salt and water, we infused acetylcholine (ACH, 2.0 micrograms/kg/min), a potent natriuretic agen, directly into the renal artery. In four dogs, ACH decreased mean arterial pressure (MAP) from 144 +/- 5 mm Hg to 113 +/- 3 mm Hg. Sodium excretion increased by about 60% on the first day of infusion and then returned rapidly toward the control value. On cessation of the ACH infusion, there was a transient but marked sodium retention, and the hypertension returned. A control infusion of ACH intravenously rather than into the renal artery in the same four dogs did not affect MAP or sodium excretion during AngII hypertension.

Measurement of subcutaneous tissue fluid pressure using a skin-cup method.

We developed a new method for measuring tissue fluid pressure in subcutaneous tissue. Porous Teflon cylinders were permanently implanted subcutaneously into the inguinal area of 10 dogs, and after several weeks a skin concavity formed in the center of each of the cylinders. A small needle attached to a recording system was inserted into the free tissue fluid lining the concavity, and the tissue fluid pressure averaged -8.8 +/- 2.7 (SD) mmHg. Next, a hollow Plexiglas cup was placed over the concavity and glued to the skin. The air pressure in the skin cup was continually adjusted (using an electromechanical servo-control system) to pull the skin upward and to hold it perfectly flat across the upper ridge of the Teflon cylinder. The simultaneously recorded needle and cup pressures averaged -9.1 +/- 2.4 and -8.6 +/- 2.6 mmHg, respectively, during steady-state conditions with the skin in a flat position. Both pressures also responded appropriately to dynamic changes in tissue fluid pressure caused by increasing and decreasing the volume of the free tissue fluid. Because the skin was flat, the equivalences of pressures above and below the skin is consistent with the hypothesis that the skin was not tethered significantly to the underlying tissues and that cup pressure accurately estimates the tissue free fluid pressure.

Capillary-to-fiber surface ratio in rat fast-twitch hindlimb muscles after chronic electrical stimulation.

We examined the relative plasticity of capillaries and fiber mitochondria in rat fast-twitch hindlimb muscles in response to chronic electrical stimulation. Specifically we addressed whether the size of the capillary-fiber interface increases in proportion to fiber mitochondrial volume, inasmuch as fiber aerobic capacity increases severalfold with chronic stimulation. Tibialis anterior and extensor digitorum longus muscles of six rats [367 +/- 17 (SD) g body wt] were stimulated (10 Hz, 8 h/day, 7 days/wk) for 28 consecutive days. Subsequently they were perfusion fixed in situ and stimulated, and contralateral control samples from the midbelly were processed for electron microscopy and morphometry. Capillary length density, capillary-to-fiber ratio, and fiber mitochondrial volume density increased two- to threefold in stimulated muscles, with no change in fiber or capillary diameter. Capillary-to-fiber surface area ratio per fiber unit mitochondrial volume was unchanged in stimulated muscles compared with contralateral controls, indicating a proportional increase in the size of the capillary-fiber interface and fiber mitochondrial volume in the muscles after chronic electrical stimulation.

Cu(II) sensitizes pBR322 plasmid DNA to inactivation by UV-B (280-315 nm).

Copper(II), in the presence of UV-B radiation (280-315 nm), can generate single-strand breaks in the sugar-phosphate backbone of pBR322 plasmid DNA. A low level of single-strand backbone breaks occurs in the presence of Cu(II) alone, but UV-B irradiation increases the rate by the more than 100-fold. Concomitant with the damage to the DNA backbone is a loss of transforming activity. Oxygen is required for generation of the single-strand breaks but not for the loss of transforming activity. A DNA glycosylase (Fpg), which participates in the repair of certain DNA nitrogenous base damage, does not repair plasmid DNA damaged by Cu(II). The hydroxyl radical scavenging compound DMSO is only somewhat effective at protecting the physical and biological properties of the DNA. These results with Cu(II) are compared to those obtained previously with pBR322 plasmid DNA in the presence of Fe(III) and UV-A.

Three species of blowfly (Diptera: Calliphoridae) collected from a human stillborn infant in the Rocky Mountains of Colorado.

In July of 1997, the remains of a human stillborn infant were found at an elevation of 2,835 m in Summit County, CO. Larvae recovered from the infant were reared to adulthood and identified as Calliphora terraenovae (Macquart), Protophormia terraenovae (Robineau-Desvoidy), and Phormia regina (Meigen). These represent new county records for high elevation species in Colorado.

The effect of anesthesia and surgery on diaphragmatic lymph vessel flow after endotoxin in sheep.

Increases in diaphragmatic lymph vessel flow (Qdi) may be important in preventing ascites because diaphragmatic lymph vessels drain the peritoneal space. However, lymphatic vessel function may be depressed in anesthetized, open chested animals. To test this hypothesis, we cannulated diaphragmatic lymph vessels in five sheep which were anesthetized with 1-2% halothane. We performed a thoracotomy and cannulated a diaphragmatic lymph vessel in each sheep. Then we infused 0.75-1.0 micrograms/kg of E. coli endotoxin intravenously and we measured Qdi and the lymph protein concentration for 2-4 hrs. The data were compared to previously reported data for five unanesthetized sheep (J. Appl. Physiol. 62:706-710, 1987). At baseline Qdi = 0.8 +/- 0.7 (SD) in the anesthetized sheep and 1.0 +/- 0.8 ml/hr in the unanesthetized sheep. After endotoxin, Qdi increased to 4.5 +/- 3.1 ml/hr in the unanesthetized sheep (p less than 0.05) but Qdi did not change in the anesthetized sheep. However, the lymph protein concentration increased similarly in each group, indicating that endotoxin caused the same degree of injury in each group. Our results indicate that diaphragmatic lymph vessel function is depressed in anesthetized, open chested sheep.

A case of suicidal hanging staged as homicide.

Suicides staged as homicides are rarely encountered by crime scene investigators. The case of one such staged homicide is presented in which the victim used restraints during a hanging. No other cases of suicidal hangings staged as homicides could be found in the forensic literature. Similar cases should be reported so additional data can be gained from these deaths to help reveal indicators of suicide rather than homicide.

Regulation of cardiac output during aldosterone-induced hypertension.

The classical haemodynamic transients of volume-loading hypertension have been difficult to demonstrate in aldosterone-induced hypertension. Because recent studies have shown that continuous whole-day measurements of cardiac output are superior to short-term recordings, we studied the transient haemodynamic effects of aldosterone-induced hypertension while monitoring arterial pressure and cardiac output (electromagnetic flow probe) continuously for 20 h a day. In six dogs maintained on a fixed sodium intake of 150 mmol/day, we infused aldosterone (12 micrograms/kg per day, intravenously) for 10 days. The aldosterone induced a progressive increase in mean arterial pressure, from a control value of 88 +/- 1 to 107 +/- 2 mmHg. Cardiac output increased progressively, reaching a peak average value on the 4th day of infusion of +14 +/- 5% above control, and remained slightly elevated throughout the infusion period. Total peripheral resistance increased slowly to a value averaging +13 +/- 4% above control. Therefore, our experiments show that aldosterone induces a primary increase in cardiac output followed by a secondary vasoconstriction, which is consistent with the classical transient haemodynamic effects of volume-loading hypertension.

100 years of mortality due to chronic obstructive pulmonary disease in Australia: the role of tobacco consumption.

BACKGROUND: Global studies of the long-term association between tobacco consumption and chronic obstructive pulmonary disease (COPD) have relied upon descriptions of trends. OBJECTIVES: To statistically analyse the relationship of tobacco consumption with data on mortality due to COPD over the past 100 years in Australia. METHODS: Tobacco consumption was reconstructed back to 1887. Log-linear Poisson regression models were used to analyse cumulative cohort and lagged time-specific smoking data and its relationship with COPD mortality. RESULTS: Age-standardised COPD mortality, although likely misclassified with other diseases, decreased for males and females from 1907 until the start of the Second World War in contrast to steadily rising tobacco consumption. Thereafter, COPD mortality rose sharply in line with trends in smoking, peaking in the early 1970s for males and over 20 years later for females, before falling again. Regression models revealed both cumulative and time-specific tobacco consumption to be strongly predictive of COPD mortality, with a time lag of 15 years for males and 20 years for females. CONCLUSIONS: Sharp falls in COPD mortality before the Second World War were unrelated to tobacco consumption. Smoking was the primary driver of post-War trends, and the success of anti-smoking campaigns has sharply reduced COPD mortality levels.

Access to health services and early age mortality in Ende, Indonesia.

OBJECTIVE: Improvements in child survival to achieve Millennium Development Goal 4 require highly accessible and effective maternal and child health (MCH) services. This article seeks to fill the gap in information for local government in Indonesia about early age mortality and access to appropriate care to inform the evaluation and planning of MCH services. METHODS: The Ende Child Mortality Survey (ECMS) was conducted in the district of Ende in Nusa Tenggara Timur (NTT), one of the poorest provinces in Indonesia. The ECMS is a cross-sectional household survey, providing information on child survival, MCH service utilisation, and socio-economic characteristics of the population. Multivariate logistic regression was conducted to examine the association of mortality, health service utilisation and socio-economic variables. RESULTS: Use of an unskilled birth attendant (45% of births) and giving birth at home are most common among the poorest and least educated women. The children of these women have the highest risk of infant mortality. The infant mortality rate differs greatly by region within Ende. Time to the preferred provider of child health care is longest in regions with the highest under-five mortality risk. CONCLUSIONS: Many women in Ende do not receive vital interventions during labour to reduce infant mortality. The ECMS demonstrates the feasibility in implementing a low cost survey to provide evidence for MCH investments to improve accessibility to appropriate health services and reduce mortality risk.

Tuberculosis mortality differentials in Indonesia during 2007-2008: evidence for health policy and monitoring.

BACKGROUND: Indonesia bears the third highest tuberculosis (TB) burden in the world. Current mortality estimates are based on notification and case fatality rates derived from the National TB Control Programme. OBJECTIVE: To report TB mortality measures for 2007-2008 based on death registration systems in selected populations in five provinces of Indonesia. METHODS: Data were compiled from sites in Central Java, Lampung, Gorontalo, West Kalimantan and Papua in 2007-2008, covering 2.5 million people. Overall mortality levels and TB mortality indicators were computed. Data quality was assessed in terms of completeness of death registration and strength of evidence in verbal autopsy questionnaires. RESULTS: A total of 1547 TB deaths were diagnosed in the five provinces. There was direct or indirect evidence of incomplete death registration at all sites. More than 90% of TB diagnoses from verbal autopsies were based on strong evidence. The results demonstrate high TB death rates in Papua, and significant mortality differentials across provinces. CONCLUSIONS: The measurement of cause-specific mortality is feasible by strengthening death registration in Indonesia. Observed TB mortality rates from five sites are baseline evidence for monitoring TB control programmes. Sustained efforts are required to develop death registration as a routine annual source of mortality data for Indonesia.

Studies of lymph modification by lymph nodes.

This paper will focus on physiological evidence for a lymph node concentrating-diluting mechanism. The mechanism is based on the finding that the protein concentration of efferent lymph leaving the node will change in the direction required to establish equilibrium of the Starling forces acting across the blood-lymph barrier of the lymph node. Therefore, the lymph proteins may become concentrated or diluted during nodal transit, depending on the direction of net fluid transfer between the lymph and blood vascular compartments; if the Starling forces are balanced perfectly, the lymph will not be altered.

Modification of lymph by lymph nodes. III. Effect of increased lymph hydrostatic pressure.

Previous studies have shown that lymph nodes function as fluid exchange chambers in which the protein concentration of lymph is changed in the direction required to establish equilibrium of the Starling forces acting across the nodal blood-lymph barrier. We examined the effect of increased lymph hydrostatic pressure on efferent lymph by use of an isolated dog popliteal node preparation in which lymph having a protein concentration averaging 27.6 +/- 1.2% (SD) of that of plasma was infused into the node at a flow rate averaging 45.6 +/- 0.2 (SD) microliter/min. We compared steady-state values of prenodal and postnodal lymph flow and protein concentration following step increases in efferent lymph pressure from 0 to over 15 mmHg. Increasing efferent lymph pressure to values less than about 8 mmHg caused the efferent lymph protein concentration to increase; however, further increases in lymph pressure caused the lymph protein concentration to decrease to values approaching those attained at very low lymph pressures. We suggest that the failure of high lymph pressure to increase lymph protein concentration might be caused by blood vessel collapse within the node, a condition believed to increase nodal blood capillary pressure and to decrease blood-lymph barrier filtration coefficient. An important finding was that increasing efferent lymph pressure caused significant amounts of lymph proteins to be lost during nodal transit. Therefore, it appears that increasing efferent lymph pressure to very high values has little effect on lymph protein concentration but has great effect on postnodal lymph protein flux.

Reflex modulation of lymphatic pumping in sheep.

Lymphatic pumping activity was examined in halothane-anesthetized sheep. A doubly cannulated preparation of the mesenteric lymph duct was "isolated" from lymph input, other than that from a constant pressure reservoir of artificial lymph attached to its inflow cannula, but had its blood supply and innervation intact. A cerebral ischemic response, evoked by injection of 2 ml air into the common carotid artery, increased both mean arterial pressure and fluid propulsion by the lymphatic. The latter rose from a control value of 45 microliters/min to a peak of 74 microliters/min. When 10(-4) M phentolamine was introduced into the lymphatic lumen, there was a transient increase followed by a sustained fall in lymph pumping. Repetition of the air injection while phentolamine was present in the duct lumen produced no increase in lymph pumping. In adrenalectomized animals, resting lymph propulsion by the mesenteric duct was depressed, and the response to air injection was attenuated but remained significantly greater than control. These results suggest that reflex activation of the sympathetic nervous system can increase lymph propulsion and that this may be augmented by the release of circulating catecholamines.

Recombination between a 3-kilobase tobacco mosaic virus transgene and a homologous viral construct in the restoration of viral and nonviral genes.

Transgenic plants harboring various plant virus sequences have shown resistance to viral infections. An environmental risk associated with the use of these plants is the possibility of forming a novel virus by recombination between challenging viruses and transgenic viral mRNA. Two experiments were designed using tobacco mosaic virus (TMV) vectors and transgenic Nicotiana benthamiana to determine if recombinant viral RNA would be detectable. N. benthamiana was transformed with a nontranslatable portion of a TMV viral vector including part of the replicase gene, the movement protein gene, a gene for green fluorescent protein (GFP), and the coat protein gene. When transformed plants were inoculated with a TMV vector coat protein mutant which could not move efficiently through the host, recombinant RNA was detected in 32% of the infected plants, although virions were not detected. When transformed plants were infected with a TMV vector with a normal coat sequence but three base changes in the GFP sequence, no recombinant RNA or virions were detected. Thus, recombinant RNA between TMV RNA and host mRNA did not accumulate to detectable levels under nonselective conditions, and though recombinant RNA did accumulate in the presence of selective pressure, an encapsidated recombinant viral population did not develop.