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Polychlorinated diphenyl ethers, dibenzo-p-dioxins, dibenzofurans and biphenyls in seals and sediment from the Gulf of Finland.

Polychlorinated diphenyl ethers (PCDEs), 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) were analyzed in seals from the Gulf of Finland and in sediments from the Gulf of Finland and near Gotland. The sediments included one surface core from both sampling sites. The seal material consisted of 14 ringed seals and 6 grey seals that all were found dead and examined for pathology. The main aims were to scrutinize levels and patterns of PCDEs for the first time in seals from the Baltic Sea and to estimate whether chlorinated compounds mentioned have an influence on an exceptional high mortality that occurred among ringed seals in the Gulf of Finland in late 1991. The concentrations of 50 congeners of tetra- through deca-CDEs analyzed ranged from < 0.3 to 62 ng/g lipid weight (lw) in seal blubber, but in the sediments PCDEs were non-detectable (tetra- through hepta-CDEs < 0.1 ng/g dry weight (dw)). In ringed seals with good nutritional status, the concentrations of almost all PCDE congeners were greater in two adult females than in specimens of younger age groups. The concentrations of PCDDs and PCDFs as TCDD-equivalents exceeded those of the coplanar (non-ortho) PCBs in sediments, whereas non- and monoortho PCBs constituted greater toxic loads as those calculated for PCDDs and PCDFs in seals. However, the levels revealed do not explain the high mortality of ringed seals.

Adipose Tissue↗

Blood is a poor substrate for monitoring pollution burdens in phocid seals.

The present study investigated how concentrations of different organochlorines (OCs) vary with nutritional condition in adult harp seal (Phoca groenlandica) females in a captive fasting experiment and in the wild. During the first part of this study seals in good condition (N= 5) were fasted for a period of 28 days and blood and blubber samples were collected at days 1, 14 and 28. Blubber OC concentrations remained unchanged throughout the experimental period, and were consistently significantly higher than concentrations in the blood. In contrast to blubber OC levels, blood OC levels showed a significant time-dependant increase. During the fasting experiment the seals lost an average of 24 kg of body mass, which is less than half the natural annual variation in this species in the wild. The second part of this study compared OC concentrations in blood and blubber from seals collected at prime condition before the breeding season (N = 10) with animals collected during molt when condition is poor (N = 7). The average mass difference between the two groups was more than 40 kg. Blood levels of most OCs were significantly higher in the thin seals compared with the levels found in the fat seals. These differences in blood OC concentrations were much greater than what was found during the fasting experiment. For example sigmaPCB levels in the blood during the fasting experiment increased by approximately 83%, while the corresponding increase in blood levels of sigmaPCB between the two other samples was 720% (from 201 to 1,447 ng/g lipid). Blubber levels of OCs from the animals in the wild were significantly higher in the thin seals compared with the fat animals. In addition, the blubber levels of OCs were significantly higher than blood levels of OCs only for the fat seals. This study demonstrates the extreme variability present in the concentrations of OCs in blood of seals in response to change in condition. Since the natural variation in condition is extreme during phocid seals' annual cycles, we recommend that blood should not be used in studies of OCs where the aim of the study is to monitor OC levels for comparative purposes or time-trend analysis.

Adipose Tissue↗

Vitamins A1 (retinol), A2 (3,4-didehydroretinol) and E (alpha-tocopherol) in the liver and blubber of lacustrine and marine ringed seals (Phoca hispida sp.).

Concentrations of vitamins A1 (retinol), A2 (3,4-didehydroretinol) and E (alpha-tocopherol) in the liver and blubber of ringed seals from Lake Saimaa (Phoca hispida saimensis), Lake Ladoga (P. h. ladogensis), the Baltic Sea (P. h. botnica) and Spitsbergen (P. h. hispida) were determined by high-performance liquid chromatography. The freshwater seals had much lower levels of vitamin A1 but higher levels of vitamin A2 than the marine seals. The concentrations of vitamin E in the livers of the subspecies studied were high compared with earlier reports of seals, but the ranges were large. The livers of the marine seals contained more vitamin E than the livers of the freshwater seals, but the levels in the blubber were uniform in all populations, except in old specimens from the Baltic. The differences between the freshwater and marine seals are suggested to be due mainly to diet. The ratios of A1 to A2 in the liver and blubber and in the fish diet were similar for the marine seals and for the freshwater seals (but differed in the marine and freshwater populations), which suggests no great differences in the absorption, transport and metabolism of the two analogues. Blubber was an important storage site for the vitamins studied, and age-dependent increases were detected, especially for vitamin E. In the 2-month to 2-year-old ringed seals of Lake Saimaa, however, the vitamin E concentration in the blubber was not affected by age.

Adipose Tissue↗

Serological survey of pre-weaned New Zealand fur seals (Arctocephalus forsteri) for brucellosis and leptospirosis.

AIM: To conduct a longitudinal serological survey for evidence of Brucella spp and Leptospira spp infection of pre-weaned New Zealand fur seals in a colony on the Otago Peninsula. METHODS: Seal pups were repeatedly captured on a monthly basis from February through to July 2001. Pups were tagged at first capture and a blood sample was taken at each capture event. A total of 163 sera were collected from 118 seal pups. Where sufficient volume was collected, the sera were tested for leptospirosis using the microscopic agglutination test (MAT), and for brucellosis using the competitive enzyme-linked immunosorbent assay (ELISA) for Brucella abortus. RESULTS: None of 128 sera from 101 seals tested positive to the ELISA for B. abortus. All tests for Leptospira interrogans serovars Grippotyphosa, Copenhageni, Bratislava and Leptospira borgpetersenii serovar Ballum were negative at a cut-off of <1/100 dilution. Positive or suspicious titres were found to L. interrogans serovars Canicola and Pomona and L. borgpetersenii serovar Hardjo. The highest titres (12,800) were found to serovar Pomona. The titre to serovar Pomona in one seal rose from <1/50 in March to 12,800 in April and was <1/50 when re-sampled in July. The titre to serovar Pomona in another seal dropped from 12,800 in May to <1/50 in June. These seals also had titres to serovar Hardjo, which rose or fell in the same manner. All suspicious or positive titres occurred in late April and early May, when the pups were approximately 4-5 months old. In June and July, all seals tested were negative. CONCLUSIONS: There was no serological evidence of Brucella infection in the pre-weaned fur seals at the colony. Positive titres to serovars Pomona, Hardjo, or Canicola suggest that a Leptospira species was present at the colony, however isolation or visualisation of the organism is required to confirm this. Care should be exercised when handling New Zealand fur seals to prevent human infection or inadvertent transfer of leptospirosis to another marine mammal species.

Age Factors↗

The helminth fauna from the common seal (Phoca vitulina vitulina, Linné, 1758) of the Wadden Sea in Lower Saxony. Part 2: Nematodes.

During the seal epidemic in 1988 and the beginning of 1989, 115 common seals found dead on the shores of the Wadden Sea of Lower Saxony were investigated for the presence of nematodes. The lungworm Otostrongylus circumlitus Railliet 1899 was found in 26.1% of the seals, the lungworm Parafilaroides gymnurus Railliet 1899 in 26.9% and the heartworm Dipetalonema spirocauda Leidy 1858 in 32.2% of the seals. In the digestive tract, two anisakid species were found, Pseudoterranova decipiens Mozgovoi 1951 in 87.8% and Contracaecum osculatum Rudolphi 1802 in 10.4% of the seals. Statistical analysis revealed a negative correlation between age of the seals and prevalence and intensity of infestation with the two lungworm species and the heartworms. Adult seals were found not to be infected with Dipetalonema spirocauda and Parafilaroides gymnurus, whereas the prevalence of the two anisakid species increased with increasing age of the seals. Pseudoterranova decipiens was found more often in autumn and winter than in summer. This parasite was more prevalent and had higher worm counts in the eastern part of the Wadden Sea than in the western part. Parafilaroides gymnurus and Dipetalonema spirocauda were found more often in seals with smaller blubber thickness than in well fed seals.

Age Factors↗

Reference values for serum biochemical parameters in free-ranging harp seals.

BACKGROUND: The harp seal (Phoca groenlandica) is one of the most important predators in the Northeastern Atlantic ecosystem. Establishing biochemical reference intervals is important for evaluating the health status of harp seals kept in captivity and for evaluating the effects of environmental changes on the health of populations in the wild. OBJECTIVE: The purpose of this study was to determine reference values for serum biochemical parameters in wild adult harp seals using readily available current methods. METHODS: Blood samples were obtained from 14 adult female harp seals and 9 suckling pups on the pack ice of the Greenland Sea in early March 1998. Seven seals were humanely killed on the ice by permission of the Norwegian Directory of Fisheries and in conjunction with several other research projects. The seals were sampled within 15 minutes postmortem. Remaining seals were captured alive and sampled via the extradural intravertebral vein. Serum biochemical parameters were measured using a Technicon Axon analyzer and included electrolytes (sodium, chloride, potassium, magnesium, and calcium), substrates (free fatty acids, triglycerides, fructosamine, and glucose), end products (urea and uric acid), and proteins (total protein, globulins, and albumin). Serum protein electrophoresis also was done. Data were tested for normality and reference limits were calculated as mean +/- 1.96 X SD. Results between groups were compared using 2-tailed t-tests. RESULTS: Serum levels of glucose and triglycerides were lower, but serum levels of urea were higher in dead animals than in animals that were captured alive. Serum levels for 7 of 17 parameters were significantly different in pups compared with adults. Separate reference intervals were calculated for adult seals and seal pups. CONCLUSION: Both sampling method and age should be considered when evaluating the results of future analysis of serum parameters in wild and captive harp seals.

Age Factors↗

Responses of harbor seal and pig heart to progressive and acute hypoxia.

Myocardial oxidative and glycolytic reserves were evaluated in four harbor seals, Phoca vitulina richardsi, and six domestic pigs, Sus scrofa (hematocrits: 58 +/- 5 and 34 +/- 1%., respectively). Progressive hypoxia was induced by lowering arterial hemoglobin-oxygen saturation in 10% decrements, each maintained for 10-min periods, until the onset of heart failure. Myocardial oxygen consumption rate (VO2), lactate release/uptake rate (L), and triple product, an index of myocardial energetic demand, were determined at each saturation level. Onset of L began in pigs at Sao2 = 57 +/- 5% and in seals at Sao2 = 35 +/- 4%. Cumulative oxygen consumption (VO2) during hypoxia, determined from the onset of cardiac lactate release, was 435 ml O2/100 g in seals and 172 ml O2/100 g in pigs. Cumulative lactate release during the same period was 14 mM/100 g in seals and 4.6 mM/100 g in pigs. The pigs' left ventricular contractile response (dP/dtmax) was greater than that of seals throughout the time of lactate release. Total myocardial energetic sources were higher in seals than in pigs, and seals were better able to tolerate myocardial hypoxia than were pigs. In a separate experiment, two seals and six pigs were made acutely hypoxic until cessation of cardiac output (seals, 17.5 min; pigs, 7.4 min) and were then reoxygenated. Both seals recovered promptly to control levels of cardiac mechanical function, whereas none of the pigs recovered. Additionally, five pigs were beta-blocked with 0.10 mg/kg of propranolol and were subjected to acute hypoxia. Tolerance to cardiac hypoxia in beta-blocked pigs was significantly increased compared with that of control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Histology of uterine leiomyoma and occurrence in relation to reproductive activity in the Baltic gray seal (Halichoerus grypus).

A high prevalence of uterine leiomyoma has been reported in Baltic gray seals aged 15 years and above. Studies on Baltic seals during the 1970s revealed high tissue concentrations of the organochlorines bis(chlorophenyl)-1,1,1-trichloroethane (DDT) and polychlorinated biphenyls (PCBs), lowered reproduction rate, and pathologic changes. In the second half of the 1970s, decreases of PCB and DDT in Baltic biota occurred, and the prevalence of pregnancies in Baltic seals increased. Between 1975 and 1997, 53 Baltic gray seal females of age 15-40 years were found dead and sent to the Swedish Museum of Natural History. Seals were autopsied and 34/53 (64%) had uterine leiomyomas. Samples from 15 were sufficiently well preserved for histologic examination. Uterine leiomyomas were found most commonly in the uterine corpus but also were observed in the uterine horns, cervix, and vagina. Cut surfaces of the leiomyomas appeared as whorled white fibrous tissue. Histologically, spindle cells were arranged in a whorl-like pattern. The nuclei were rod-like and strikingly uniform in shape and size. Mitotic figures were rare. Immunohistochemical staining of the tumors showed a positive reaction to antibodies recognizing smooth muscle actin. Reproductively active gray seals have an ovarian corpus luteum or albicans for most of the year. In 22/34 (65%) gray seals with uterine leiomyomas, ovaries did not contain corpora. In gray seals without macroscopically detected uterine leiomyoma, ovaries from 6/19 (32%) seals had no corpora. It is possible that the development of leiomyoma in the seals is associated with organochlorines and the previous low reproductive activity.

Actins↗

Reproductive biology of seals.

The reproductive biology of seals is fascinating in many aspects. As in most mammals, the time of onset of puberty in seals is variable. Once sexually mature, most but not all seals are seasonally mono-oestrous, with highly synchronized breeding seasons. They have evolved as either terrestrial or aquatic copulators, although a few species mate in a variety of habitats. Their mating strategies are diverse, ranging from serial monogamy to extreme polygyny. Gestation in seals is characterized by an embryonic diapause, which is obligate in most species. Reactivation of the blastocyst is followed by a placental gestation. All species of seal require a terrestrial (including ice floes) habitat for parturition. Lactation differs between the two seal families: phocid seals have an intense period of maternal investment, during which the mothers fast; otariid seals have a prolonged lactation during which intense bouts of suckling are interspersed by days of separation from their pups while the mother forages at sea. Although the anatomy and functional morphology of seals has been well described, less is known of the endocrinology of reproduction. This is due mainly to the logistical difficulties that researchers experience in collecting serial samples from a species that is relatively difficult to handle. This article reviews the basic anatomy and physiology, and our current understanding of the comparative aspects of reproduction in seals. Reproductive behaviours as well as the influences of environmental factors, such as photoperiod, nutrition and xenobiotics, are also discussed.

Animals↗

Podosome and sealing zone: specificity of the osteoclast model.

The bone resorption function of osteoclasts is dependent on the integrity of the actin cytoskeleton. Depending on the substratum upon which the osteoclasts are spread, there are two different structures of actin known as podosomes and the sealing zone. To understand the specific properties and relationship of podosomes and the sealing zone, we used live-cell imaging of cultured osteoclasts. When cultured on extracellular matrix components, podosomes in these cells are organized in higher-ordered structures. These are clustered podosomes that will arrange later into dynamic short-lived rings which finally expand to the cell periphery to form a stable long-lived podosome belt in fully differentiated cells. In osteoclasts, this specific podosome patterning is under the control of microtubules (MTs). Indeed, nocodazole treatment does not affect podosome formation but only the transition between clusters/rings and belts. During this transition, MTs accumulate a specific post-translational modification of tubulin by acetylation. This process is repressed by an inhibitory pathway involving the GTPase Rho, its effector mDIA2 and the recently discovered tubulin deacetylase HDAC6. The specific function of this acetylation is still unknown but is also observed in active osteoclasts forming a sealing zone which is also MT dependent. Thus, it appears that the podosome belt is reminiscent of the sealing zone. Indeed, podosome belts and sealing zones are characterized by their overall stability. Despite their similar behavior, a sealing zone is not formed by fusion of podosomes. The formation of a podosome belt or a sealing zone is controlled by the external environment. Indeed, only the bone mineral fraction, known as apatite crystal, is able to induce sealing zone formation in mature osteoclasts. Contact of osteoclasts with apatite stimulates the non-receptor tyrosine kinase c-Src and the GTPase Rho in order to form the sealing zone. As we will discuss in this review, it appears that podosomes and the sealing zone are strikingly linked.

Actin Cytoskeleton↗

Laboratory development and field demonstration of self-sealing/self-healing landfill liner.

The self-sealing/self-healing (SS/SH) barrier concept is based on the principle that two or more parent materials placed in vertical or horizontal layers will react at their interfaces to form insoluble reaction products. These products constitute a seamless impermeable seal, which is resistant to the transmission of leachate and contaminants. A SS/SH liner formulation was developed in the laboratory and demonstrated at the Sudokwon landfill site in South Korea. Laboratory testing results indicated that a seal with a hydraulic conductivity less than 10(-9) m/s formed after two to four weeks of curing at room temperature, and the seal healed itself after it was fractured. The use of the soil from the Sudokwon landfill site instead of sand as the matrix of the parent materials in the SS/SH liner retarded the sealing and healing of the seal, but did not show an obvious effect on the overall sealing and healing capacity of the seal at early stages. The construction and installation of the field demonstration SS/SH liner were carried out in the same way as for a soil cement liner. The quality of the liner was ensured by the enforcement of quality analysis/quality control procedures during installation. A single sealed ring infiltration test was performed on the field demonstration liner 36 days after the installation was completed. The measurement of water infiltration rate indicated that the liner healed after it was fractured. However, the long-term sealing and healing capacity needs to be further investigated.

Environment Design↗

Evaluation of time required for recontamination of coronally sealed canals medicated with calcium hydroxide and chlorhexidine.

AIM: To determine in vitro the time required for recontamination of coronally sealed canals medicated with either calcium hydroxide (CaOH2), 2% chlorhexidine gel (CG) or with a combination of both. METHODOLOGY: Eighty intact, caries-free, premolar teeth with straight roots and mature apices were selected for the study. After biomechanical preparation of 75 teeth, they were randomly divided into nine groups according to the intracanal medicament and the coronal seal with 'Intermediate Restorative Material' (IRM) as follows: (i) 10 teeth medicated with CG, coronally unsealed; (ii) 10 teeth medicated with CaOH2, coronally unsealed; (iii) 10 teeth medicated with CaOH2 + CG, coronally unsealed; (iv) 10 teeth medicated with CG + coronal seal; (v) 10 teeth medicated with CaOH2 + coronal seal; (vi) 10 teeth medicated with CG + CaOH2 + coronal seal; (vii) 10 teeth without intracanal medicament and coronally sealed; (viii) 5 teeth without intracanal medicament and coronally unsealed, used as the positive control group (PC); (ix) 5 teeth with intact crowns used as the negative control group (NC). Glass flasks were filled with Brain Heart Infusion broth (BHI), so that only the root apex was in contact with the broth, while the crown was immersed in human saliva + BHI (3:1). The flasks were then incubated at 37 degrees C in an atmosphere of 10% CO2, and microbial growth was checked daily. RESULTS: All specimens of the PC showed contamination within 1 day of incubation, while the NC showed no evidence of broth turbidity. Recontamination was detected after an average time of 3.7 days in the unsealed canals medicated with CG, 1.8 days in the group medicated with CaOH2 and 2.6 days in the group medicated with CaOH2 + CG. When the crowns were sealed with IRM, recontamination was detected within 13.5 days in the canals medicated with CG, after 17.2 days in the group medicated with CaOH2 and after 11.9 days in the group medicated with CG + CaOH2. The group with no medication, but sealed with IRM, showed recontamination after 8.7 days. There were statistically significant differences between the teeth with or without coronal seal (P<0.05). CONCLUSION: The coronal seal delayed but did not prevent leakage of microorganisms. There was no difference between the various medicaments.

Anti-Infective Agents, Local↗

Fibrin glue sealing of polytetrafluoroethylene vascular graft anastomoses: comparison with oxidized cellulose.

To evaluate potential clinical applications of nonautologous fibrin glue (FG) as a hemostatic agent in vascular surgery, we compared its efficacy to oxidized regenerated cellulose (OC) in hemostatically sealing polytetrafluoroethylene (PTFE) vascular graft anastomoses. PTFE grafts (4 mm wide and 4 to 6 cm in length) were placed to each femoral artery in a heparinized canine model, in end-to-end fashion in half of the dogs and in end-to-side fashion in the remaining dogs. Each set of graft-arterial anastomoses was then sealed with either FG or OC, determined randomly, followed by simultaneous measurement of blood loss through the graft anastomoses and needle holes. There was significantly less bleeding from anastomoses sealed with FG compared with those sealed with OC, regardless of whether the anastomoses sealed with FG compared with those sealed with OC, regardless of whether the anastomosis was constructed in end-to-end (p less than 0.03) or end-to-side (p less than 0.004) fashion; overall, the operative blood loss for grafts sealed with FG was 14 +/- 6 (mean +/- standard error of the mean) vs 99 +/- 27 ml/min for those sealed with OC (p less than 0.001). In the early postoperative period, significant groin hematomas occurred more frequently in grafts sealed with OC compared with those sealed with FG. Microscopic examination of graft-arterial specimens harvested at postoperative intervals ranging from 1 day to 3 months revealed no significant inflammatory reaction with either hemostatic agent; after 2 to 3 weeks, paired specimens appeared histologically similar despite previous treatment with either FG or OC.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

On the ecology of the harbour seal Phoca vitulina in the Wadden Sea: population dynamics, residue levels, and management .

The harbour seal population in the Dutch Wadden Sea decreased significantly during the last decades. Calculations based on bounty data revealed that the population decreased from about 2700 in 1950 to about 900 in 1959. Annual aerial surveys--which were carried out since that time--showed a slight increase due to the stop of hunting. However, after 1964 a new decline occurred and since 1974 the population stays at a level of about 450 specimens. During 1974 to 1978 the population dynamics of the population have been studied Frequent aerial surveys provided data on the size of the population. These data have been used in a simulation model and the birth rate and the initial juvenile mortality were calculated. During boat trips an indication of the age composition was obtained by measuring track widths. By comparing these results with similar results from a stable population in Schleswig Holstein it appeared: (1) that juvenile mortality in the first weeks in the Dutch population is higher than that in Schleswig Holstein but the overall mortality of pups in both areas in their first three months of life is of the same order; (2) that pup production in the Dutch population is low compared to the population in Schleswig Holstein; (3) that apparently immigration from elsewhere occurs. To investigate the contribution of environmental pollution to the decline of the Dutch seal population tissues of dead, stranded animals originating from Schleswig Holstein, Denmark and the Netherlands were collected and analyzed for PCBs, o,p'-DDT, p,p'-(DDT, DDE, TDE), dieldrin, aldrin, endrin, endosulfan, alpha, beta, gamma,-HCH, HCB, QCB (pentachlorobenzene), HEPO, total mercury, methyl-mercury, selenium and bromium. Considering epidemiological and experimental data on the effects of PCBs on mammalian reproduction, strong support is obtained for the hypothesis that PCBs are responsible for the decreased reproduction in seals from the Dutch Wadden Sea. if PBCs are responsible for the decrease of the Dutch seal population, measure of all North Sea countries are urgently required because these PCBs may not only be a hazard to seals but also to other animals and even man. Production and use of PCBs should be limited and used PCBs should be collected and destroyed. However, even if an immediate ban on PCB's would be effected, the effects of PCBs because of their persistent character are likely to last many years. For that reason it may be assumed that the seal population in the western Wadden Sea still faces a difficult period in the years to come. In order to lead this population through this difficult period, all possible measures enhancing its continued existence should be taken. Since the seals in the Wadden Sea form one population maximum result may be expected from measures applying to all seals in the Wadden Sea. Thus international cooperation is necessary. The following measures are proposed: Continued interdiction of hunting in order to obtain a maximum number of animals taking part in reproduction. Establishment of seal reserves and, additionally supporting seal nursery stations in order to guarantee a maximum reproductive output. However, it has to be stressed that these measures are not effective if at the same time the main cause of the decrease is not found and brought under control.

Animals↗

Comparison of the LMA-classic with the new disposable soft seal laryngeal mask in spontaneously breathing adult patients.

BACKGROUND: The laryngeal mask airway LMA-Classic has been used widely in clinical practice. A new disposable supraglottic airway device, the Soft Seal LM, has been introduced recently. In a randomized study, the authors compared the LMA-Classic and the disposable Soft Seal LM in terms of their clinical performance, cuff pressures during nitrous oxide anesthesia, position of the laryngeal mask in situ by fiberoptic evaluation, and morbidity in a wide range of routine general surgery procedures. METHODS: A total of 200 adult patients were randomly assigned to a size 4 laryngeal mask in two equal-sized groups for airway management during surgery: (1) LMA-Classic (Intavent Orthofix Ltd., Maidenhead, Berkshire, United Kingdom); or (2) Soft Seal LM (Portex Ltd., Hythe, Kent, United Kingdom). Anesthesia was administered with fentanyl, propofol, nitrous oxide, oxygen, and sevoflurane. The variables studied were ease of insertion, fiberoptic view, time in situ, incidence of blood on the laryngeal mask at the time of removal, and the incidence of postoperative sore throat at 2 and 24 h. The laryngeal mask cuff pressures were measured continuously. Intracuff pressure limitation was not attempted. RESULTS: The LMA-Classic and the Soft Seal LM showed similar clinical performances, as shown by their insertion time (successful insertion at first attempt was achieved within 20 s in 97% with LMA-Classic trade mark vs. 95% with Soft Seal LM), fiberoptic evaluation of the anatomic position of the laryngeal mask, and satisfactory anesthesia conditions. Laryngeal mask cuff pressures increased from 45 to 100.3 mmHg in the LMA-Classic and from 45 to 46.8 mmHg in the Soft Seal LM (P < 0.001). Macroscopic blood was seen on only four occasions in the LMA-Classic group. The incidence of sore throat was significantly increased at 2 h postoperatively when using the LMA-Classic, although there was no difference at 24 h after surgery. CONCLUSIONS: In spontaneously breathing adult patients requiring a size 4 laryngeal mask airway, the new disposable Soft Seal LM device is an acceptable alternative to the reusable LMA-Classic trade mark, resulting in a good laryngeal seal and offering similar clinical performance. Cuff pressures increase substantially when the LMA-Classic is used but not when using the Soft Seal LM. There was less trauma to patients using the Soft Seal LM, as assessed by the incidence of sore throat in the early postoperative period.

Adolescent↗

The 1988 and 2002 phocine distemper virus epidemics in European harbour seals.

We present new and revised data for the phocine distemper virus (PDV) epidemics that resulted in the deaths of more than 23 000 harbour seals Phoca vitulina in 1988 and 30,000 in 2002. On both occasions the epidemics started at the Danish island of Anholt in central Kattegat, and subsequently spread to adjacent colonies in a stepwise fashion. However, this pattern was not maintained throughout the epidemics and new centres of infection appeared far from infected populations on some occasions: in 1988 early positive cases were observed in the Irish Sea, and in 2002 the epidemic appeared in the Dutch Wadden Sea, 6 wk after the initiation of the outbreak at Anholt Island. Since the harbour seal is a rather sedentary species, such 'jumps' in the spread among colonies suggest that another vector species could have been involved. We discussed the role of sympatric species as disease vectors, and suggested that grey seal populations could act as reservoirs for PDV if infection rates in sympatric species are lower than in harbour seals. Alternatively, grey seals could act as subclinical infected carriers of the virus between Arctic and North Sea seal populations. Mixed colonies of grey and harbour seal colonies are found at all locations where the jumps occurred. It seems likely that grey seals, which show long-distance movements, contributed to the spread among regions. The harbour seal populations along the Norwegian coast and in the Baltic escaped both epidemics, which could be due either to genetic differences among harbour seal populations or to immunity. Catastrophic events such as repeated epidemics should be accounted for in future models and management strategies of wildlife populations.

Age Factors↗

Some problems in sealing gas-filled glass ampoules.

We have studied recently the ends of hand-sealed and machine-sealed, gas-filled ampoules of borosilicate glass. The hand-sealed ampoules were of two types: tip-sealed and draw-sealed. The openings in the tip-sealed ampoules were estimated to range from 5 to 10 mu; in the machine-sealed ampoules the helix-like openings were less than approximately 10 mu. From the dimensions and nature of the openings we conclude (1) that the usual, simple methods used to test for "leakers" are not successful for small bore channels because pressure differences are less than one atmosphere and the test-time period insufficient, (2) that the failure of ampoules to seal may be due to the physical properties of glass and if this is so, ampoules containing liquid or freeze-dried preparations under gases cannot be sealed completely by ordinary means, and (3) that complete, satisfactory sealing can be done by dipping the ends of the ampoules into an elastomer solution which when cured provides an effective barrier even when stored at -70 degrees C for 12 months.

Drug Packaging↗

A ferrofluidic seal specially designed for rotary blood pumps.

One of the key technologies required for rotary blood pumps is sealing of the motor shaft. A ferrofluidic seal was developed for an axial flow pump. The seal body was composed of a plastic magnet and two pole pieces. This seal was formed by injecting ferrofluid into the gap between the pole pieces and the motor shaft. To contain the ferrofluid in the seal and to minimize the possibility of ferrofluid making contact with blood, a shield with a small cavity was provided on the pole piece. Sealing pressure of the seal was measured. The sealing pressure was maintained at more than 23.3 kPa (175 mm Hg) for a motor speed up to 11,000 rpm. The specially designed ferrofluidic seal for sealing out liquids is useful for axial flow blood pumps.

Blood Flow Velocity↗