Sorafenib is associated with a reduced rate of tumour growth and liver function deterioration in HCV-induced hepatocellular carcinoma

BACKGROUND & AIMS

Sorafenib has been the standard of care for patients with advanced hepatocellular carcinoma and although immunotherapeutic approaches are now challenging this position, it retains an advantage in HCV-seropositive patients. We aimed to quantify the rate of tumour progression in patients receiving sorafenib and relate this figure to survival, both overall, and according to viral status.

METHODS

Using serial data from an international clinical trial we applied a joint model to combine survival and progression over time in order to estimate the rate of tumour growth as assessed by tumour burden and serum alpha-fetoprotein, and the impact of treatment on liver function.

RESULTS

High tumour burden at baseline was associated with an increased risk of death. In patients still alive at the end of the study, the progression in relation to tumour burden was very low compared to those who died within the study. Overall, the change in mean tumour burden was 0.12 mm per day or an absolute growth rate of 3.6 mm/month. Median doubling time was 665 days. For those who progressed above 0.12 mm per day or the 12% rate, median survival was 234 days compared to 384 days if the rate was below 12%. Tumour growth rate and serum alpha-fetoprotein rise were significantly lower in those who were HCV seropositive as was the rate of decline in liver function. These results were replicated in 2 independent patient groups.

CONCLUSION

Our analysis suggests that sorafenib treatment is associated with improved survival in patients with advanced hepatocellular carcinoma mainly by decreasing the rate of tumour growth and liver function deterioration among patients with HCV infection.

LAY SUMMARY

Among patients receiving sorafenib for advanced hepatocellular carcinoma the rate of tumour growth (as assessed by changes in tumour size and the biomarker alpha-fetoprotein) and the deterioration of liver function is less in those who have the hepatitis C virus, than in those who do not.

CamGFR v2: A New Model for Estimating the Glomerular Filtration Rate from Standardized or Non-standardized Creatinine in Patients with Cancer

PURPOSE

Management of patients with cancer, specifically carboplatin dosing, requires accurate knowledge of glomerular filtration rate (GFR). Direct measurement of GFR is resource limited. Available models for estimated GFR (eGFR) are optimized for patients without cancer and either isotope dilution mass spectrometry (IDMS)- or non-IDMS-standardized creatinine measurements. We present an eGFR model for patients with cancer compatible with both creatinine measurement methods.

EXPERIMENTAL DESIGN

GFR measurements, biometrics, and IDMS- or non-IDMS-standardized creatinine values were collected for adult patients from three cancer centers. Using statistical modeling, an IDMS and non-IDMS creatinine-compatible eGFR model (CamGFR v2) was developed. Its performance was compared with that of the existing models Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Modification of Diet in Renal Disease (MDRD), Full Age Spectrum (FAS), Lund-Malmö revised, and CamGFR v1, using statistics for bias, precision, accuracy, and clinical robustness.

RESULTS

A total of 3,083 IDMS- and 4,612 non-IDMS-standardized creatinine measurements were obtained from 7,240 patients. IDMS-standardized creatinine values were lower than non-IDMS-standardized values in within-center comparisons (13.8% lower in Cambridge; P < 0.0001 and 19.3% lower in Manchester; P < 0.0001), and more consistent between centers. CamGFR v2 was the most accurate [root-mean-squared error for IDMS, 14.97 mL/minute (95% confidence interval, 13.84-16.13) and non-IDMS, 15.74 mL/minute (14.86-16.63)], most clinically robust [proportion with >20% error of calculated carboplatin dose for IDMS, 0.12 (0.09-0.14) and non-IDMS, 0.17 (0.15-0.2)], and least biased [median residual for IDMS, 0.73 mL/minute (-0.68 to 2.2) and non-IDMS, -0.43 mL/minute (-1.48 to 0.91)] eGFR model, particularly when eGFR was larger than 60 ml/minute.

CONCLUSIONS

CamGFR v2 can utilize IDMS- and non-IDMS-standardized creatinine measurements and outperforms previous models. CamGFR v2 should be examined prospectively as a practice-changing standard of care for eGFR-based carboplatin dosing.

Multicenter Validation of the CamGFR Model for Estimated Glomerular Filtration Rate

Important oncological management decisions rely on kidney function assessed by serum creatinine-based estimated glomerular filtration rate (eGFR). However, no large-scale multicenter comparisons of methods to determine eGFR in patients with cancer are available. To compare the performance of formulas for eGFR based on routine clinical parameters and serum creatinine not calibrated with isotope dilution mass spectrometry, we studied 3620 patients with cancer and 166 without cancer who had their glomerular filtration rate (GFR) measured with an exogenous nuclear tracer at one of seven clinical centers. The mean measured GFR was 86 mL/min. Accuracy of all models was center dependent, reflecting intercenter variability of isotope dilution mass spectrometry-creatinine measurements. CamGFR was the most accurate model for eGFR (root-mean-squared error 17.3 mL/min) followed by the Chronic Kidney Disease Epidemiology Collaboration model (root-mean-squared error 18.2 mL/min).

Cancer Immunotherapy Trials Underutilize Immune Response Monitoring

Immune-related radiological and biomarker monitoring in cancer immunotherapy trials permits interrogation of efficacy and reasons for therapeutic failure. We report the results from a cross-sectional analysis of response monitoring in 685 T-cell checkpoint-targeted cancer immunotherapy trials in solid malignancies, as registered on the U.S. National Institutes of Health trial registry by October 2016. Immune-related radiological response criteria were registered for only 25% of clinical trials. Only 38% of trials registered an exploratory immunological biomarker, and registration of immunological biomarkers has decreased over the last 15 years. We suggest that increasing the utilization of immune-related response monitoring across cancer immunotherapy trials will improve analysis of outcomes and facilitate translational efforts to extend the benefit of immunotherapy to a greater proportion of patients with cancer.

Climate effects on late-season flight times of Massachusetts butterflies

Although the responses of living organisms to climate change are being widely investigated, little attention has been given to such effects late in the growing season. We studied the late-season flight times of 20 species of butterflies in a geographically limited region, the state of Massachusetts in the USA, by examining change in dates of flight over a 22-year period and in response to average monthly temperature and precipitation. By analyzing the last 10% of each year's observations reported by observers of the Massachusetts Butterfly Club, we found that seven species remain in flight significantly later into the fall than they did two decades earlier, while two species show reduced late-season flight. Life history characteristics of the species, particularly voltinism and average fall flight dates, influenced whether warmer fall months led to increases or decreases in fall flight. Warmer Novembers often led to later fall flight, and wetter Augusts usually extended fall flight. These results document the effects of climate on late-season flight times of butterflies, add to an understanding of how warmer autumn conditions alter the phenology of different butterfly species, and show the usefulness of citizen science data.

New Model for Estimating Glomerular Filtration Rate in Patients With Cancer

Purpose The glomerular filtration rate (GFR) is essential for carboplatin chemotherapy dosing; however, the best method to estimate GFR in patients with cancer is unknown. We identify the most accurate and least biased method. Methods We obtained data on age, sex, height, weight, serum creatinine concentrations, and results for GFR from chromium-51 (51Cr) EDTA excretion measurements (51Cr-EDTA GFR) from white patients ≥ 18 years of age with histologically confirmed cancer diagnoses at the Cambridge University Hospital NHS Trust, United Kingdom. We developed a new multivariable linear model for GFR using statistical regression analysis. 51Cr-EDTA GFR was compared with the estimated GFR (eGFR) from seven published models and our new model, using the statistics root-mean-squared-error (RMSE) and median residual and on an internal and external validation data set. We performed a comparison of carboplatin dosing accuracy on the basis of an absolute percentage error > 20%. Results Between August 2006 and January 2013, data from 2,471 patients were obtained. The new model improved the eGFR accuracy (RMSE, 15.00 mL/min; 95% CI, 14.12 to 16.00 mL/min) compared with all published models. Body surface area (BSA)-adjusted chronic kidney disease epidemiology (CKD-EPI) was the most accurate published model for eGFR (RMSE, 16.30 mL/min; 95% CI, 15.34 to 17.38 mL/min) for the internal validation set. Importantly, the new model reduced the fraction of patients with a carboplatin dose absolute percentage error > 20% to 14.17% in contrast to 18.62% for the BSA-adjusted CKD-EPI and 25.51% for the Cockcroft-Gault formula. The results were externally validated. Conclusion In a large data set from patients with cancer, BSA-adjusted CKD-EPI is the most accurate published model to predict GFR. The new model improves this estimation and may present a new standard of care.

Peripheral nerve surgery: the role of high-resolution MR neurography

High-resolution MRN is becoming increasingly available due to recent technical advancements, including higher magnetic field strengths (eg, 3T), 3D image acquisition, evolution of novel fat-suppression methods, and improved coil design. This review describes the MRN techniques for obtaining high-quality images of the peripheral nerves and their small branches and imaging findings in normal as well as injured nerves with relevant intraoperative correlations. Various microsurgical techniques in peripheral nerves, such as neurolysis, nerve repairs by using nerve grafts, and conduits are discussed, and MRN findings of surgically treated nerves are demonstrated.

MR neurography of neuromas related to nerve injury and entrapment with surgical correlation

MR imaging of peripheral nerves has been described in relation to abnormalities such as nerve injury, entrapment, and neoplasm. Neuroma formation is a known response to peripheral nerve injury, and here we correlate the MRN appearance of postinjury neuroma formation with intraoperative findings. We also present the MR imaging features of surgical treatment with a synthetic nerve tube and nerve wrap on postoperative follow-up imaging.

Highly diverged homologs of Saccharomyces cerevisiae mitochondrial mRNA-specific translational activators have orthologous functions in other budding yeasts

Translation of mitochondrially coded mRNAs in Saccharomyces cerevisiae depends on membrane-bound mRNA-specific activator proteins, whose targets lie in the mRNA 5'-untranslated leaders (5'-UTLs). In at least some cases, the activators function to localize translation of hydrophobic proteins on the inner membrane and are rate limiting for gene expression. We searched unsuccessfully in divergent budding yeasts for orthologs of the COX2- and COX3-specific translational activator genes, PET111, PET54, PET122, and PET494, by direct complementation. However, by screening for complementation of mutations in genes adjacent to the PET genes in S. cerevisiae, we obtained chromosomal segments containing highly diverged homologs of PET111 and PET122 from Saccharomyces kluyveri and of PET111 from Kluyveromyces lactis. All three of these genes failed to function in S. cerevisiae. We also found that the 5'-UTLs of the COX2 and COX3 mRNAs of S. kluyveri and K. lactis have little similarity to each other or to those of S. cerevisiae. To determine whether the PET111 and PET122 homologs carry out orthologous functions, we deleted them from the S. kluyveri genome and deleted PET111 from the K. lactis genome. The pet111 mutations in both species prevented COX2 translation, and the S. kluyveri pet122 mutation prevented COX3 translation. Thus, while the sequences of these translational activator proteins and their 5'-UTL targets are highly diverged, their mRNA-specific functions are orthologous.

Direct-injection NMR (DI-NMR): a flow NMR technique for the analysis of combinatorial chemistry libraries

A new tool for analyzing compound libraries by NMR has been developed. Aliquots of solution-state samples (between 120 and 350 microL) are directly injected, using a standard liquids handler, into an NMR (LC-NMR) flow probe. Automated NMR software tracks--and suppresses--intense signals arising from the nondeuterated solvents used (if any) and acquires high-sensitivity one-dimensional 1H NMR spectra. An 88-member combinatorial library, dissolved in DMSO and stored in a 96-well microtiter plate, has been analyzed a number of ways using this technique. This nondestructive technique, which we call direct-injection NMR (DI-NMR) and which is embodied in our versatile automated sample changer (VAST) hardware, has proven to be both routine and robust. Our success in automatically acquiring the NMR data for entire plates of library compounds (within 4-8 h) has caused us to develop new ways to display and analyze the resulting NMR data, as will be shown here.

Manatee Mortality in Puerto Rico

/ The most pressing problem in the effective management of the West Indian manatee (Trichechus manatus) in Puerto Rico is mortality due to human activities. We assessed 90 cases of manatee strandings in Puerto Rico based on historical data and a coordinated carcass salvage effort from 1990 through 1995. We determined patterns of mortality, including type of event, condition of carcasses, spatial and temporal distribution, gender, size/age class, and the cause of death. The spatial distribution of stranding events was not uniform, with the north, northeast, and south coasts having the highest numbers. Six clusters representing the highest incidence included the areas of Fajardo and Ceiba, Bahía de Jobos, Toa Baja, Guayanilla, Cabo Rojo, and Rio Grande to Luquillo. The number of reported cases has increased at an average rate of 9.6%/yr since 1990. The seasonality of stranding events showed a bimodal pattern, from February through April and in August and September. Most identified causes of death were due to human interaction, especially captures and watercraft collisions. Natural causes usually involved dependent calves. From 1990 through 1995, most deaths were attributed to watercraft collisions. A reduction in anthropogenic mortality of this endangered species can be accomplished only through education and a proactive management and conservation plan that includes law enforcement, mortality assessment, scientific research, rescue and rehabilitation, and inter- and intraagency cooperation.

Nerocila benrosei n. sp. (Isopoda: Cymothoidae), an external parasite of hogfishes from the northern Bahamas

Nerocila benrosei n. sp. is described from the hogfish, Lachnolaimus maximus (Walbaum), and the Spanish hogfish, Bodianus rufus (Linnaeus), (Perciformes: Labridae) from the northern Bahamas. Nerocila benrosei differs from all species of Nerocila by having the body of females 1.4-1.9 times as wide as long, instead of 2.0-3.0 times, and pleopods 1 and 2 lacking accessory lamellae. It differs from the only species of Nerocila with which it overlaps geographically, N. lanceolata (Say, 1818), by having the lateral margins of pleonites 1-5 strongly produced ventrally, coxae 5-7 manifestly shorter than the posterolateral projection of the respective pereonite, and a vaulted dorsal surface. The species of Nerocila in the northwestern Atlantic have almost mutually exclusive geographic ranges: New England to Panama, including Bermuda and the northern coast of Cuba (Nerocila lanceolata); Brazil to Trinidad and Tobago (Nerocila fluviatilis Schiödte and Meinert, 1881); and the northern Bahamas and Bermuda (Nerocila benrosei). No species of Nerocila have been reported from the insular Caribbean. Nerocila benrosei appears to be highly host and site specific.

Genetic evidence for the role of GDP-mannose in plant ascorbic acid (vitamin C) biosynthesis

Vitamin C (L-ascorbic acid; AsA) acts as a potent antioxidant and cellular reductant in plants and animals. AsA has long been known to have many critical physiological roles in plants, yet its biosynthesis is only currently being defined. A pathway for AsA biosynthesis that features GDP-mannose and L-galactose has recently been proposed for plants. We have isolated a collection of AsA-deficient mutants of Arabidopsis thaliana that are valuable tools for testing of an AsA biosynthetic pathway. The best-characterized of these mutants (vtc1) contains approximately 25% of wild-type AsA and is defective in AsA biosynthesis. By using a combination of biochemical, molecular, and genetic techniques, we have demonstrated that the VTC1 locus encodes a GDP-mannose pyrophosphorylase (mannose-1-P guanyltransferase). This enzyme provides GDP-mannose, which is used for cell wall carbohydrate biosynthesis and protein glycosylation as well as for AsA biosynthesis. In addition to genetically defining the first locus involved in AsA biosynthesis, this work highlights the power of using traditional mutagenesis techniques coupled with the Arabidopsis Genome Initiative to rapidly clone physiologically important genes.

Helminths from a stranded manatee in the Dominican Republic

Endangered West Indian manatees (Trichechus manatus) are known to be parasitized by a number of helminths and ectoparasites. Records of parasitic associations exist for Florida, Mexico, Guyana, Brazil, Cuba and recently for Puerto Rico. Parasites of manatees in other Caribbean areas have not been documented, particularly from Hispaniola. We report on the occurrence of a species of nematode and of two trematodes from a 238-cm male manatee from Portillo (19 degrees 20' N, 69 degrees 35' W), Las Terrenas, in the Dominican Republic. Three species of helminths were collected, including the opisthotrematid Cochleotrema cochleotrema, the ascarid Heterocheilus tunicatus, and the paramphistomid trematode Chiorchis fabaceus. The documentation of these helminths constitutes the first record of these parasites and host relationships for Hispaniola and the second for the northeastern Caribbean.

Metazoan parasites and other symbionts of cetaceans in the Caribbean

The parasite fauna in cetaceans from Puerto Rico, the Virgin Islands, and the larger Caribbean region is poorly known. We provide the first records for parasite biodiversity among a diverse assemblage of cetaceans from the Caribbean Sea. Internal and external parasites and commensals were collected from stranded whales and dolphins salvaged in Puerto Rico, the United States and British Virgin Islands, Jamaica, and Venezuela between 1989 and 1997. A total of 47 individuals of 16 species of whales and dolphins (15 odontocetes and 1 mysticete) was examined. Overall, parasites and commensals were found in 34 (72.3%) animals, representing 13 species of odontocetes and 1 mysticete. Eighteen species of endoparasitic helminths were found, including 8 species of nematodes, 2 digeneans, 6 cestodes, and 2 acanthocephalans. Three species of whale-lice and 2 species of barnacles were also collected.

The histologic anatomy of the volar plate

The volar plate (VP) is critical to the stability of the proximal interphalangeal joint. This study clarifies the macro- and micro-architectural structure of the VP and correlates these findings with its functional properties. Microscopic evaluation of cadaver specimens revealed a trilaminar structure of the VP with differential orientation and organization of collagen fibers in the volar, central core, and dorsal check rein sections of the plate. This description differs from the existing literature and adds to the understanding of the functional properties of the VP. The most important finding is a dense "basket weave" of collagen fibers oriented in 2 perpendicular planes within the central core of the VP. This orientation may contribute primarily to the resistance of the VP to both longitudinal and torsional stress. This study adds to the understanding of the histologic basis for the function of the VP and the mechanisms involved in its injury.

Environmental stress sensitivity of an ascorbic acid-deficient Arabidopsis mutant

L-ascorbic acid (vitamin C) is a powerful reducing agent found in millimolar concentrations in plants, and is proposed to play an important role in scavenging free radicals in plants and animals. However, surprisingly little is known about the role of this antioxidant in plant environmental stress adaptation or ascorbate biosynthesis. We report the isolation of soz1, a semi-dominant ozone-sensitive mutant that accumulates only 30% of the normal ascorbate concentration. The results of genetic approaches and feeding studies show that the ascorbate concentration affects foliar resistance to the oxidizing gas ozone. Consistent with the proposed role for ascorbate in reactive oxygen species detoxification, lipid peroxides are elevated in soz1, but not in wild type following ozone fumigation. We show that the soz1 mutant is hypersensitive to both sulfur dioxide and ultraviolet B irradiation, thus implicating ascorbate in defense against varied environmental stresses. In addition to defining the first ascorbate deficient mutant in plants, these results indicate that screening for ozone-sensitive mutants is a powerful method for identifying physiologically important antioxidant mechanisms and signal transduction pathways. Analysis of soz1 should lead to more information about the physiological roles and metabolism of ascorbate.

Transfer of incompatibility factors between stocks of Nasonia (= Mormoniella) vitripennis

The stock of Nasonia vitripennis marked by the nuclear eye color mutation "tinged" (ti) shows nonreciprocal cytoplasmic incompatibility with wild-type (+) strains. Homogenates prepared from ti female pupae and injected into + female pupae caused 39% of the recipients to acquire the incompatibility characteristics of the ti donors. When eggs obtained from ti females were fragmented and injected into + female pupae, or when the ti egg cytoplasm was injected into chick eggs and yolk sac homogenates were subsequently injected into + female pupae, 28% of the recipients acquired ti-type incompatibility characteristics. Results from passage of the egg cytoplasm through 0.23-microns millipore filters showed successful transfer of the incompatibility and suggest that the incompatibility system in N. vitripennis has two components: a bacterium and a smaller agent.

Neobenedenia pargueraensis n. sp. (Monogenea: Capsalidae) from the red hind, Epinephelus guttatus, and comments about Neobenedenia melleni

Neobenedenia pargueraensis n. sp. from Epinephelus guttatus of Puerto Rico differs from all known species in possessing scoop-shaped accessory sclerites with pointed tips. It is most similar to Neobenedenia melleni and Neobenedenia longiprostata but differs from the former in having a fenestrate ovary and from the latter in that the ducts of the accessory glands are short, terminating just anterior to the vitelline reservoir rather than reaching the caudal end of the body. It differs from both species in having smooth rather than lobate testes. Neobenedenia melleni occurs throughout the tropical and subtropical western North Atlantic including Bermuda. It kills aquarium and aquaculture fishes with massive infestations and is a severe restraint on the culture of tilapia in sea water in the Caribbean.

Influence of collection methods on the occurrence of alimentary canal helminth parasites in fish

The effect of collecting trauma on the metazoan parasites in the alimentary canal of French grunts, Haemulon flavolineatum (Desmarest) (Perciformes: Haemulidae), was evaluated by comparing the number and species of parasites in 10-fish lots that were identical except for collecting technique. Collecting techniques included speared (dead), speared through the caudal peduncle (live), trapped, dipnetted at night, and ostracitoxin exposed. Dead, trapped, and toxin-stressed fish had no alimentary canal parasites, whereas speared-live and night-dipnetted fish had comparable numbers of parasites. Fish collected by using apparently traumatic techniques quickly expelled their alimentary canal metazoan parasites. Our results cast doubt on the reliability of traditional fish parasite surveys, studies on population dynamics of fish parasites, and experiments that employ these traumatic collecting methods.

Aldose reductase expression in human diabetic retina and retinal pigment epithelium

The conversion of glucose to sorbitol by aldose reductase (AR) and its subsequent intracellular accumulation have been implicated in the pathogenesis of diabetic cataracts. There is also evidence linking AR activity with retinal capillary basement membrane thickening in galactosemic rats, suggesting a possible role in diabetic retinopathy. In this study, we explored one feature of this issue by examining diabetic and nondiabetic eyes for immunoreactive AR. AR was immunohistochemically undetectable in the retinal pigment epithelia (RPE) and neural retinas of nondiabetic human eyes. Weak, focal staining for AR was present unilaterally in the RPE of 1 of 11 diabetic patients without pathologic ocular findings and in 43% of diabetic patients with mild ocular findings. Retinal positivity was found (unilaterally) in only 2 of 19 individuals from either of these mildly affected groups. Fifty-five percent of patients with background retinopathy demonstrated AR positivity in the RPE, and half of these expressed AR in the RPE of both eyes. Of the individuals with proliferative diabetic retinopathy, 87.5% showed bilateral staining in the RPE. Retinal positivity was present in 36% of background retinopathy and 75% of proliferative retinopathy cases, demonstrating a positive correlation between AR expression and the severity of the disorder. In weakly staining retinas, only the ganglion cell bodies, nerve fibers, and Müller cells were positive, whereas in intensely staining cases, virtually the entire retina, except for the rod outer segments, was positive. Eyes from patients who had had diabetes less than or equal to 6 yr were negative for AR, but those from long- term-diabetic patients (14-45 yr) manifested positively.(ABSTRACT TRUNCATED AT 250 WORDS)

Digenetic trematodes of marine fishes of Okinawa, Japan

Between May and September 1985, 348 fishes representing 50 families, 107 genera, and 152 species from the coastal waters of Okinawa were examined for digenetic flukes. Ten families (Lepocreadiidae, Opistholebetidae, Gyliauchenidae, Fellodistomidae, Acanthocolpidae, Opecoelidae, Bucephalidae, Cryptogonimidae, Syncoeliidae, and Hemiuridae), representing 29 genera and 34 species of digenetic flukes were recorded. Seven new geographic locality records and 25 new host records were established. Possibly 2 new species, one being a species of the genus Metadena from Meiacanthus grammistes and the other a species of the genus Mesolecitha from Plectorhynchus chaetodontoides, were detected. Most infections were of a single species, and although prevalence and intensity were low, host specificity was high. Only 3 of the 34 species identified transgressed family bounds in their definitive hosts.

High glucose concentrations inhibit protein synthesis in retinal pigment epithelium in vitro

There is mounting evidence suggesting functional and structural alterations in the retinal pigment epithelium (RPE) in experimental and clinical diabetes. In this study we examined the effect of high glucose concentrations on human RPE cells in vitro. After 24-hr incubation in media supplemented with glucose (19.5 mM, 25.5 mM, and 45.5 mM) and prepared both with and without osmotic adjustment, there was no significant effect on [3H]thymidine or [3H]uridine incorporation into TCA-precipitable material. There was, however, a significant decrease in [35S]methionine incorporation which became more marked with increasing glucose concentrations. This could not be attributed to increased osmolarity caused by the additional glucose as it occurred in isosmolar high glucose media. 3-O-methyl glucose, a non-metabolized glucose analog, did not have the same effect, suggesting that metabolism of glucose may be important. Resolution of newly synthesized proteins by gel electrophoresis and autoradiography suggests a generalized decrease in protein synthesis. These data suggest that elevated glucose levels cause a significant metabolic alteration in RPE cells in vitro.

Admissions to a rural hospital in the West Nile District of Uganda over a 27 year period

An analysis is presented of data on all 30 129 inpatient admissions to a mission hospital in the West Nile District of Uganda in the 27 year period from July 1951 to August 1978. For most of this period the hospital was staffed by the same two doctors. For each patient admitted, a record was made of their age (adult or child), sex, place of residence, duration of stay in hospital, diagnosis and vital status at discharge. The annual number of admissions increased steadily from around 300 in 1952 to over 1600 in 1966 and subsequently declined to about 900 in 1977. Sixty-five per cent of admissions were medical, 12% surgical, 11% obstetric and 9% gynaecological. Thirty per cent of admissions were children (aged 0-9 years). Forty-five per cent of admissions were from those resident in the same county as the hospital and another 20% were from an immediately adjacent county. Infective and parasitic conditions (including respiratory diseases) accounted for over 60% of admissions among children and over 38% of admissions among adults (excluding obstetric patients). The six most common causes of admission were: uncomplicated delivery (2308 admissions), pneumonia (2020), hookworm (1999), malaria (1806), schistosomiasis (1742) and diarrhoea (1041). In total 1960 deaths were recorded (6.5% of all admissions). High case fatality rates were observed for tetanus (61%), immaturity (54%), meningitis (38%), kwashiorkor (21%), other malnutrition (19%) and anaemia (19%). A striking increase in the number of admissions for measles was observed in the period 1976 to 1978. Admission rates for schistosomiasis (S. mansoni) appeared to be highest from counties adjacent to the Nile and 104 deaths were recorded among the 1742 patients with this as the primary diagnosis. Admissions for diabetes, as a percentage of all admissions increased from 0.2% in 1951-54 to 1.5% at the end of the study period. Marked seasonal variations in admission patterns were found for diarrhoea, measles, meningitis and respiratory infections, the last two, but not diarrhoea, being most common in the wettest months. Admissions for malaria showed no strong seasonal associations. Despite the limitations of hospital-based data, it is argued that the data analysed provide a reasonable indication of the important causes of severe morbidity and mortality in the district. Furthermore, some of the changes in admission patterns over time are likely to represent true changes in disease rates rather than artefacts of diagnosis or referral. The analyses presented indicate the value of simple record systems, carefully maintained.

A temporal and spatial study of the synthesis and degradation of water-soluble and insoluble proteins in galactosemic rat lenses

Events of synthesis and degradation of water-soluble and -insoluble rat lens proteins were examined during a 21-day period of galactose-induced cataractogenesis. Epithelial cells continued to synthesize both fractions of proteins throughout the duration of the experiment. There were few qualitative changes in the pattern of proteins expressed and the rate of synthesis did not decrease. In contrast, synthesis of both water-soluble and -insoluble proteins by the cortical cells decreased and then became totally inhibited indicating no selective or differential inhibition of synthesis of one protein fraction, but that both water-soluble and -insoluble proteins in the cortical cells are equally affected by the metabolic changes associated with galactose-induced cataractogenesis. The cells within the nuclear region of control lenses were capable of incorporating [35S]-methionine into protein. This synthesis was completely abolished in 7- and 14-day nuclear cells. Labeled proteins were found to be present in the 21-day nuclear preparation to a level almost three times greater than that observed in the control nucleus. Degradation was minimal in both fractions of epithelial proteins, whereas selective degradation of proteins from both fractions was apparent in 14- and 21-day cortical cells. At day 14, the water-soluble protein profile from nuclear cells became less complex with the loss of several major bands, but these bands as well as some unique bands appeared at day 21. The profile of water-insoluble nuclear proteins remained unchanged over 21 days.

Endemic Kaposi's sarcoma: incidence and risk factors in the West Nile District of Uganda

Out of 72 Kaposi's sarcoma patients diagnosed between 1951 and March 1976 at Kuluva Hospital, West Nile District, Uganda, 64 with known co-ordinates were plotted on a map. Sixty-two of these were noted to live at an altitude of 853 metres or more (greater than or equal to 2,800 feet). Twenty-four patients were thought to be still alive and visits were made to their homes. Space-time grouping of four cases was noted on two occasions, although analysis did not reveal statistically significant clustering. A case-control study employing an interview questionnaire with 32 variables was performed on 19 patients and their age- and sex-matched neighbourhood controls, and sera were collected from both groups and from their families for estimation of viral antibody titres. The results demonstrated that cases tended to be post-pubertal males, a high proportion of whom had been bitten by a blood-sucking insect identified as being similar to Haematopota. Both cases and controls had raised antibody levels to cytomegalovirus, but cases obtained their drinking water more commonly from rivers whereas controls tended to use water from springs, boreholes or pipes.

Epstein-Barr virus markers in a series of Burkitt's lymphomas from the West Nile District, Uganda

In an epidemiological survey in the West Nile District of Uganda, 70 pathologically confirmed BL cases were detected over a 5-yr period; this corresponded to an annual incidence rate of 1.6 per 100,000 general population or about 5 per 100,000 children in the age group 5-14 yr. Of the confirmed cases which were examined by EBV/DNA molecular hybridization, 96% were found to contain an average of 38 EBV genome equivalents per tumour cell, whereas none of the examined unconfirmed cases did. Duplicate hybridization assays in two laboratories were in close agreement. Serological testing showed that 91% of the confirmed BL cases had elevated EBV/VCA titres (greater than or equal to 160) and 64% were EA(D)-positive (greater than or equal to 10). Most of the cases with high EBV/genome content had high VCA titres, but there was a poor correlation between the two parameters among all cases. This study confirms that in high BL incidence areas the association between EBV and this lymphoma is almost constant, whereas it is exceptional in low-incidence areas. This further supports the aetiological implication of EBV in the endemicity of this tumor in equatorial Africa.

Periosteal transection for correction of angular limb deformities in foals

Seventeen foals with angular limb deformities of the distal end of the radius (valgus: 26 limbs), distal end of the tibia (valgus: 6 limbs), and distal end of the 3rd metacarpal bone/metatarsal bone (varus: 4 limbs) were treated surgically by means of hemicircumferential division of the periosteum proximal to the involved growth plate, at the concave side of the bone. There was some correction in all cases. The best results were seen in the radius, where 22 of 25 limbs were corrected to a deviation of 4 degrees or less. Satisfactory correction was obtained in the 6 tibias, the 2 third metacarpal bones, and the 2 metatarsal bones.

Effect of temperature during potassium arrest on myocardial metabolism and function

Past studies have not established the optimal myocardial temperature range for hyperkalemic arrest but have generated controversy regarding the safety of exposing the myocardium to more profound levels of hypothermia. We therefore used the isolated working rat heart model of ischemic arrest to study the metabolic and functional effects of cardioplegia at the full range of temperatures pertinent clinically. Experimental conditions were designed to reliably control and maintain myocardial temperature during the 60 minute arrest period. We found that nearly full recovery of function occurred when hearts were arrested at or below 16 degrees C. High-energy phosphate levels measured immediately after arrest were better maintained at 4 degrees and 8 degrees C, despite evidence of decreased anaerobic glycolysis. When measured after the recovery period, high-energy phosphate levels returned to somewhat less than control levels in all groups arrested at or below 24 degrees C. Myocardial glucose utilization was best preserved in hearts arrested at or below 12 degrees C. We found no evidence that greater myocardial edema resulted from arrest at colder temperatures. Severe and permanent damage was observed when hearts were arrested at or above 28 degrees C. In this model, therefore, the best overall metabolic and functional protection occurred when hearts were maintained at 12 degrees C or below potassium-induced cardioplegia. Our results support the idea that cold injury to the heart does not occur and that colder temperatures provide better protection from ischemic myocardial injury.

Final case reporting from the Ugandan prospective study of the relationship between EBV and Burkitt's lymphoma

A prospective epidemiological study was carried out in the West Nile District of Uganda from 1972 to 1979 in order to investigate the aetiological role of the Epstein-Barr virus (EBV) in Burkitt's lymphoma (BL). By 1976, fourteen BL cases had been detected among the 42,000 children originally bled in the study area. Testing of sera from BL candidates and neighbourhood controls showed that children who develop BL later have EBV/VCA titres several dilutions higher than their age- and sex-matched neighbours. This appearance of a strong EBV activity long before BL development was taken as evidence of a causal role of EBV in BL. In order to add to the unique material of pre-bled BL cases, BL detection was continued up to March 1979 when field work became impossible in Uganda. Two additional pre-bled BL cases were found during this extension of the study. The serological and virological evaluation of these additional cases showed that the EBV/VCA titres, but not the EA and EBNA titres, were about two dilutions higher in the BL candidates than in the controls. Hybridization assays showed that both lymphomas contained EBV/DNA in the tumour cells. These additional results thus confirm the findings in the first 14 cases and strengthen the epidemiological evidence for a causal role of the EBV in endemic BL.

Anterior spinal artery syndrome with chronic traumatic aortic aneurysm

Shortly after severe blunt chest trauma, a young man experienced neurological symptoms suggestive of a spinal cord lesion at the lower thoracic level. The symptoms resolved at first, but then recurred 3 years later and progressed slowly. Neurological workup failed to define the cause until a thoracic aortogram showed an aneurysm in the middle portion of the descending aorta in close proximity to a vessel supplying the anterior spinal artery. After the operative repair with precautions taken to avoid further neurological injury, the neurologic deficit resolved partially. Because of the potential for symptomatic spinal cord ischemia resulting from lesions of the aorta, angiographic delineation of the spinal cord blood supply is valuable in planning operative repair.

Early calcific stenosis of aortic and mitral Ionescu-Shiley valves in a patient with bioprosthetic infection

The clinical course of a patient with bioprosthetic failure of aortic and mitral Ionescu-Shiley valves (which contain bovine pericardial leaflets) is presented. Failure occurred in less than 4 months and was due to infection that resulted in calcification and severe stenosis. On examination of tissue specimens under light and electron microscopes, the pathological process was seen to be similar o that occurring with infected porcine prostheses.

Use of cold cardioplegic solution for vein graft distention and preservation: a light and scanning electron microscopic study

To evaluate the effect of a cardioplegic solution on the endothelium of the saphenous vein, portions of this vein were harvested from each of 5 patients undergoing coronary artery bypass operation. Each sample was divided into five segments. One segment was distended with heparinized saline solution, one with heparinized blood, and one with heparinized cardioplegic solution (25 mEq of potassium per liter). All of the distending solutions were kept at 10 degrees C, and pressure was carefully limited to 200 mm Hg. The fourth segment of vein was distended with heparinized saline solution but no effort was made to limit distending pressure, and the fifth segment was not distended. All samples were then examined with light and scanning electron microscopy. There were no great morphological differences in the endothelium of veins distended to 200 mm Hg with saline solution, blood, or cardioplegic solution. The morphology of these samples compared favorably with the control vein endothelium although scattered areas of endothelial disruption were present in every sample. Veins distended without pressure control showed massive endothelial disruption. The particular solution used to distend the sephenous veins is not as important as limiting the distending pressure.

Electrical coupling among heart cells in the absence of ultrastructurally defined gap junctions

Cells from the ventricles of 7-day chick embryos were aggregated into spheroidal clusters by 48 hr of culture on a gyratory platform. All aggregates beat spontaneously and rhythmically. Microelectrode impalement of widely separated cells within aggregates indicated that they were coupled, as evidenced by a mean coupling ratio (delta V2/ delta V1) of 0.81 +/- 0.09, and by simultaneity of intrinsic electrical activity (action potentials and subthreshold voltage fluctuation). In freeze-fracture preparations, the cell surfaces contained numerous small groups of intramembrane protein (IMP) particles, arranged in macular clusters, and linear and circular arrays. Using the criterion of 4 clustered IMP particles to defined a minimal gap junction, 0.27% of the total P-face examined was devoted to gap junctional area. Within such clusters particles were packed at about 8200/micrometer2; in nonjunctional regions, particles were scattered at a density of about 2000/micrometer2. When exposed to cycloheximide (CHX: 50 micrograms/ml) for 24--48 hr, coupling ratio declined to 0.44. This decrease could be attributed largely to leakiness of the nonjunctional membrane. Aggregates continued to beat rhythmically and in a coordinated fashion even after 72 hr in inhibitor. However, between 3--21 hr in CHX gap junctional area declined to 0.10%, and all particle clusters disappeared from the P-faces of aggregates in CHX for 24 or 48 hr. Neither macular nor linear particle arrays were seen. We conclude that organized gap junctions are unnecessary for electrotonic coupling between embryonic heart cells. These findings support the idea that low-resistance cell-to-cell pathways may exist as isolated channels scattered throughout the area of closely apposed plasma membranes.

Multiprogrammable pacemakers

Since 1962 it has been possible to change, by noninvasive means, the functions of implanted pacemakers. This study reports a 3-year multicentre experience, in 164 patients, with a multiprogrammable pacemaker that offers a wide range of choices within five variables: mode, rate, pulse width, sensitivity and telemetry (over 3000 combinations). In a selected series 83% of implanted pacemakers were programmed for medical indications and 100% for multiparameter follow-up studies. The advantage and disadvantages of three are compared. There is little doubt that multiprogrammable pacemakers can reduce the frequency of reoperation in any large series.

Protein degradation and synthesis during recovery from myocardial ischemia

Rates of synthesis and degradation of heart protein were measured during 30 or 60 min of myocardial ischemia and during the 30 or 60 min following these ischemic periods. During ischemia, rates of protein synthesis and degradation were reduced. Resumption of control rates of coronary flow after 30 min of ischemia resulted in complete restoration of creatine phosphate and partial recovery of ATP (75%), developed pressure (79%), and cardiac output (80%). After 60 min of ischemia, restoration of flow completely restored creatine phosphate but resulted in poor recovery of ATP (57%), developed pressure (26%), and cardiac output (63%). During the recovery phase, rates of protein synthesis and degradation of protein to free amino acids were the same as in hearts that had been perfused for a comparable period as working aerobic preparations. These findings were consistent with inhibition of an initial step in proteolysis during the period of ischemia followed by return to control rates of degradation when oxygen delivery and energy levels were restored.

Nuclear magnetic resonance study of ligand exchange on hexakis(1,1,3,3-tetramethylurea)yttrium(III)

The first reported direct study of monodentate ligand exchange on yttrium(III) shows the rate of 1,1,3,3-tetramethylurea exchange on [Y {O=C(NMe2)2}6]3+ to be independent of free ligand concentration consistent with the operation of either a dissociative mechanism or an interchange mechanism where the encounter complex stability constant is ≥ 300. Typical data from this 270-MHz 1H n.m.r. study, where rate of ligand exchange = kex 6[Y {O=C(NMe2)2}63+] are as follows: kex(250 K) = 25�1 s-1, ΔH‡ = 27.1 � 0.5 kJ mol-1 and ΔS‡ = -108 � 2 J K-1 mol-1 for a CD3CN solution in which [Y{O=C(NMe2)2}63+] and free [O=C(NMe2)2] are 0.0039 and 0.028 mol dm-3 respectively. The preparations of [Y(ligand)6] (ClO4)3 where the ligand is O=C(NMe2)2, O=C(Me)(NHMe), O=C(Me)(NMe2), or O=C(Me)(NEt2) are also reported. Solutions of the latter three species and their respective ligands exhibit spectra consistent with ligand exchange being in the fast exchange limit of the n.m.r. time scale down to the lowest accessible temperatures.