65Zn2+ Transport by lobster hepatopancreatic lysosomal membrane vesicles

In crustaceans, the hepatopancreas is the major organ system responsible for heavy metal detoxification, and within this structure the lysosomes and the endoplasmic reticulum are two organelles that regulate cytoplasmic metal concentrations by selective sequestration processes. This study characterized the transport processes responsible for zinc uptake into hepatopancreatic lysosomal membrane vesicles (LMV) and the interactions between the transport of this metal and those of calcium, copper, and cadmium in the same preparation. Standard centrifugation methods were used to prepare purified hepatopancreatic LMV and a rapid filtration procedure, to quantify 65Zn2+ transfer across this organellar membrane. LMV were osmotically reactive and exhibited a time course of uptake that was linear for 15-30 sec and approached equilibrium by 300 sec. 65Zn2+ influx was a hyperbolic function of external zinc concentration and followed Michaelis-Menten kinetics for carrier transport (Km = 32.3 +/- 10.8 microM; Jmax = 20.7 +/- 2.6 pmol/mg protein x sec). This carrier transport was stimulated by the addition of 1 mM ATP (Km = 35.89 +/- 10.58 microM; Jmax = 31.94+/-3.72 pmol/mg protein/sec) and replaced by an apparent slow diffusional process by the simultaneous presence of 1 mM ATP+250 microM vanadate. Thapsigargin (10 microM) was also a significant inhibitor of zinc influx (Km = 72.87 +/- 42.75 microM; Jmax =22.86 +/- 4.03 pmol/mg protein/sec), but not as effective in this regard as was vanadate. Using Dixon analysis, cadmium and copper were shown to be competitive inhibitors of lysosomal membrane vesicle 65Zn2+ influx by the ATP-dependent transport process (cadmium Ki = 68.1 +/- 3.2 microM; copper Ki = 32.7 +/- 1.9 microM). In the absence of ATP, an outwardly directed H+ gradient stimulated 65Zn2+ uptake, while a proton gradient in the opposite direction inhibited metal influx. The present investigation showed that 65Zn2+ was transported by hepatopancreatic lysosomal vesicles by ATP-dependent, vanadate-, thapsigargin-, and divalent cation-inhibited, carrier processes that illustrated Michaelis-Menten influx kinetics and was stimulated by an outwardly directed proton gradient. These transport properties as a whole suggest that this transporter may be a lysosomal isoform of the ER Sarco-Endoplasmic Reticulum Calcium ATPase.

Unplanned admissions following ambulatory plastic surgery--a retrospective study

INTRODUCTION

Admission for overnight or longer hospital stay from a day-case unit is an unwelcome event. This audit was designed to identify the incidence of unplanned admissions and also to detect the potential factors for such overstays.

PATIENTS AND METHODS

Details of plastic surgical day-case patients were obtained from the hospital records for a period of 6 months (February 2002 to July 2002).

RESULTS

The total number of unplanned admissions was 28 (3.55%). High rates were recorded in patients above the age of 80 years, male patients and body mass index > 30 kg/m2. Duration of surgery (> 45 min) and waiting time in the day surgery unit (> 2.5 h) had significant correlation with the overstays. Grade of the surgeon was not an important determinant factor. Of procedures which resulted in an unexpected admission, the most frequent were otoplasty (8.4%; n = 71) and fasciectomy for Dupuytren's contracture (14.5%; n = 41). Unexpected admissions were also high following rhinoplasty and nipple reconstruction but the total number of operations performed were not significant (n = 12 in each group). Overall, the cause of the overstays were mostly surgical (71.4%) followed by anaesthetic (28.5%) and social (7.1%).

DISCUSSION

With an overall unplanned admission rate of 3.55%, our unit is close to the national standard of 2-3%, as advocated by The Royal College of Surgeons of England. Postoperative bleeding (60%) was the most important surgical reason for overstays followed by intravenous antibiotics, wound drainage, excessive duration of the procedure and additional, unplanned procedures. Among the anaesthetic factors, postoperative pain was the leading cause (62.5%) followed by nausea, vomiting and adverse anaesthetic reaction.

CONCLUSIONS

The reasons for unplanned admissions are multifactorial and merit appropriate patient selection and proper estimation of the disease process.

Physiological characterization of 45Ca2+ and 65Zn2+ transport by lobster hepatopancreatic endoplasmic reticulum

The crustacean hepatopancreas is an epithelial-lined, multifunctional organ that, among other activities, regulates the flow of calcium into and out of the animal's body throughout the life cycle. Transepithelial calcium flow across this epithelial cell layer occurs by the combination of calcium channels and cation exchangers at the apical pole of the cell and by an ATP-dependent, calcium ATPase in conjunction with a calcium channel and an Na+/Ca2+ antiporter in the basolateral cell region. The roles of intracellular organelles such as mitochondria, lysosomes, and endoplasmic reticulum (ER) in transepithelial calcium transport or in transient calcium sequestration are unclear, but may be involved in transferring cytosolic calcium from one cell pole to the other. The ER membrane has a complement of ATP-dependent calcium ATPases (SERCA) and calcium channels that regulate the uptake and possible transfer of calcium through this organelle during periods of intense calcium fluxes across the epithelium as a whole. This investigation characterized the mechanisms of calcium transport by lobster hepatopancreatic ER vesicles and the effects of drugs and heavy metals on them. Kinetic constants for 45Ca2+ influx under control conditions were K(n) (m)=10.38+/-1.01 microM, J(max)=14.75+/-1.27 pmol/mg protein x sec, and n=2.53+/-0.46. The Hill coefficient for 45Ca2+ influx under control conditions, approximating 2, suggests that approximately two calcium ions were transported for each transport cycle in the absence of ATP or the inhibitors. Addition of 1 mM ATP to the incubation medium significantly (P<0.01) elevated the rate of 45Ca2+ influx at all calcium activities used and retained the sigmoidal nature of the transport relationship. The kinetic constants for 45Ca2+ influx in the presence of 1 mM ATP were K(n) (m)=12.76+/-0.91 microM, J(max)=25.46+/-1.45 pmol/mg protein x sec, and n=1.95+/-0.15. Kinetic analyses of ER 65Zn2+ influx resulted in a sigmoidal relationship between transport rate and zinc activity under control conditions (K(n) (m)=38.63+/-0.52 microM, J(max)=19.35+/-0.17 pmol/mg protein x sec, n=1.81+/-0.03). The Addition of 1 mM ATP enhanced 65Zn2+ influx at each zinc activity, but maintained the overall sigmoidal nature of the kinetic relationship. The kinetic constants for zinc influx in the presence of 1 mM ATP were K(n) (m)=34.59+/-2.31 microM, J(max)=26.09+/-1.17 pmol/mg protein x sec, and n=1.96+/-0.17. Both sigmoidal and ATP-dependent calcium and zinc influxes by ER vesicles were reduced in the presence of thapsigargin and vanadate. This investigation found that lobster hepatopancreatic ER exhibited a thapsigargin- and vanadate-inhibited, SERCA-like, calcium ATPase. This transporter displayed cooperative calcium transport kinetics (Hill coefficient, n approximately 2.0) and was inhibited by the heavy metals zinc and copper, suggesting that the metals may reduce the binding and transport of calcium when they are present in the cytosol.

Experience with different treatment modules in hidradenitis suppuritiva: a study of 106 cases

BACKGROUND

Hidradenitis suppuritiva, a disease of the apocrine sweat glands, has always been a challenging area to the plastic and reconstructive surgeon. The aetiology is idiopathic and medical treatment offers temporary relief only. Radical surgical excision, therefore, is the mainstay of active management.

AIM

To present and evaluate a series of 106 patients of hidradenitis suppuritiva treated in the regional plastic surgery unit of southeast Scotland between January 1990 and December 2000.

PATIENTS

Median age at onset was 36 years (range 17-70 years). The patients were predominantly females (88.78%) and heavy smokers (98.1%). Median age before active surgical intervention was six years (range 1-30 years). The patients were divided into a mild group (n=64) and a severe group (n = 42). All patients had broad-spectrum antibiotics and multiple incision and drainage procedures before referral from general practitioners, dermatologists or general surgeons. One hundred sites were managed by primary closure (mostly in the 'mild' group); 29 resurfaced with split skin grafts and 14 with local, fasciocutaneous or musculocutaneous flaps (mostly in the 'severe' group). Median postoperative follow-up period was three years (range 1-7 years).

RESULTS

In the 'primary closure' series, recurrence rate requiring at least one secondary operation was 69.88%. There was no recurrence, no serious complications and no revision operations in the 'graft' and the 'flap' series.

CONCLUSION

A high index of suspicion is required before contemplating primary closure in hidradenitis suppuritiva, even in the ' mild' variety. This condition should always be treated aggressively by radical excision of all hair-bearing areas and reconstructed with a graft or a flap.

Propagation of stress fracture of the patella

Anterior knee pain in athletes is common and usually self limited. There should be a high index of suspicion and low threshold for special imaging in cases with acute onset and specific tenderness. The risk of propagation of stress fracture of the patella in athletes is highlighted. The case report presented illustrates the potential sequence of events.

Prolonged use of electronic games--a word of caution

Post-traumatic hyperextension deformity of the thumb due to rupture of volar plate is a rare but clinically important phenomenon. These injuries are usually related to ball sports like basketball and handball. However, we describe an unusual association in an elderly patient with chronic use of an electronic game, which merits a high index of suspicion for early diagnosis and treatment to prevent long-term complications.

Calcium regulation in crustaceans during the molt cycle: a review and update

Epithelial cells of the gut, gills, antennal glands and integument regulate calcium concentrations in crustaceans during the molt cycle. A cellular calcium transport model has been proposed suggesting the presence of calcium pumps, cation antiporters and calcium channels in transporting epithelial membranes that regulate the movements of this cation across the cell layer. Basolateral calcium transport during postmolt appears mainly regulated by the low affinity NCX antiporter, while calcium regulating 'housekeeping' activities of these cells in intermolt are controlled by the high affinity calcium ATPase (PMCA). A model is proposed for the involvement of the epithelial ER in the massive transepithelial calcium fluxes that occur during premolt and postmolt. This model involves the endoplasmic reticulum SERCA and RyR proteins and proposed cytoplasmic unstirred layers adjacent to apical and basolateral plasma membranes where calcium activities may largely exceed those in the bulk cytoplasmic phase. A result of the proposed transepithelial calcium transport model is that large quantities of calcium can be moved through these cells by these processes without affecting the low, and carefully controlled, bulk cytoplasmic calcium activities.

Spontaneous keloids in siblings

The authors report two rare cases of 'non-syndromic spontaneous keloids' occuring in siblings. This represents another unexplored area in the field of 'keloid challenge', warranting further research and development.

Mechanisms of heavy-metal sequestration and detoxification in crustaceans: a review

This review is an update of information recently obtained about the physiological, cellular, and molecular mechanisms used by crustacean organ systems to regulate and detoxify environmental heavy metals. It uses the American lobster, Homarus americanus, and other decapod crustaceans as model organisms whose cellular detoxification processes may be widespread among both invertebrates and vertebrates alike. The focus of this review is the decapod hepatopancreas and its complement of metallothioneins, membrane metal transport proteins, and vacuolar sequestration mechanisms, although comparative remarks about potential detoxifying roles of gills, integument, and kidneys are included. Information is presented about the individual roles of hepatopancreatic mitochondria, lysosomes, and endoplasmic reticula in metal sequestration and detoxification. Current working models for the involvement of mitochondrial and endoplasmic reticulum calcium-transport proteins in metal removal from the cytoplasm and the inhibitory interactions between the metals and calcium are included. In addition, copper transport proteins and V-ATPases associated with lysosomal membranes are suggested as possible sequestration processes in these organelles. Together with several possible cytoplasmic divalent and trivalent anions such as sulfate, oxalate, or phosphate, accumulations of metals in lysosomes and their complexation into detoxifying precipitation granules may be regulated by variations in lysosomal pH brought about by bafilomycin-sensitive proton ATPases. Efflux processes for metal transport from hepatopancreatic epithelial cells to the hemolymph are described, as are the possible roles of hemocytes as metal sinks. While some of the cellular processes for isolating heavy metals from general circulation occur in the hepatopancreas and are beginning to be understood, very little is currently known about the roles of the gills, integument, and kidneys in metal regulation. Therefore, much remains to be clarified about the organs and mechanisms involved in metal homeostasis in decapod crustaceans.

Evaluation of pulse polio immunization in some districts of West Bengal & Assam

A cross-sectional non-interventional survey was carried out in 5 districts of West Bengal and one district of Assam to find out the extent of coverage during IPPI. It was observed that in the recent rounds of IPPI, more than 95% coverage was observed in all the surveyed districts excepting in 24 Parganas South where coverage was around 92%. Situation at the Goalpara district further needed attention, as the coverage during February 03 as well as in the past two rounds were 90.13%, 88.13%, and 91.04% respectively. In all these districts booths were the main sites for IPPI dose though 1/3rd to 1/4th of the beneficiaries received immunization at home also. It was also observed that around 10% of the beneficiaries were not administered any PPI dose in the either of the rounds, in 24 Parganas (south) & Murshidabad districts, from where maximum number of Poliomyelitis cases were reported. At Goalpara it was 19%. Main reason for not being covered with PPI doses in either of the rounds in all the districts excepting Kolkata was "Not aware of the need for additional doses". In Kolkata "child sick" was the main reason. Health workers were main source of information of PPI in South 24 Parganas (67.13%), Malda (58.25%) & West Midnapur (54%). At Murshidabad "announcement through mike" (61.25%) was the main source of information while in Kolkata, TV was the main source (67.13%). Miking (56.38%) was the main source of information for PPI at Goalpara district of Assam. It was observed that involvement of multiple methods & media of communication was helpful in disseminating dates & other information of PPI.

Proton transfer reaction of a new orthohydroxy Schiff base at room temperature and 77 K

One new orthohydroxy Schiff base, 2-(N-benzyl-alpha-iminoethyl)naphthol (BEIN) has been synthesized. The proton transfer reaction of BEIN has been investigated by means of absorption, steady state and time resolved fluorescence spectroscopy in different solvents at room temperature and 77K. The behavior of BEIN in ethanol and water, has been studied in neutral, acidic and basic conditions. Excited state intramolecular proton transfer (ESIPT) is evidenced by a large Stokes shifted ( approximately 11,000 cm-1) fluorescence in solid crystalline media at room temperature. We present the observation of phosphorescence both in non-polar and protic solvents at 77K. The observed decay dynamics of the phosphorescence and delayed fluorescence indicates that the triplet state can be attributed to the cis-keto form. The molecular structures are determined by B3LYP/6-31G** calculation. From theoretical study it is suggested that the strengthening of hydrogen bond result from the steric repulsion of the phenyl ring. The presence of benzene ring increases the proton transfer barrier in case of BEIN compared to previously studied 7-ethylsalicylidenebenzylamine (ESBA).

Genetic resistance of Barbari and Jamunapari kids to natural infection with gastrointestinal nematodes

An investigation was made in 252 Barbari and Jamunapari kids to assess their resistance to natural infection with gastrointestinal (GI) nematodes and to establish indicator traits for such resistance in Indian goats. The indicator traits, faecal egg counts (FEC) and packed cell volume (PCV) were affected by various genetic and non-genetic factors. There were no breed differences in the FEC or PCV at 3, 6 or 9 months of age. Jamunapari male kids had a higher FEC than the female kids at 6 months of age. However, Barbari female kids had a higher FEC than the respective male kids at 9 months of age. At 6 months of age in both breeds, the kids born in the spring (March-April) had a higher FEC than those born in the autumn (October-November). The FEC of kids at 9 months of age was higher than at 3 or 6 months of age. Sire had a significant effect on PCV at 6 and 9 months of age. The kids born in the autumn had a higher PCV than those born in the spring. The PCV of male Barbari kids differed significantly from that of female kids at all the ages. The correlation coefficient of FEC on both body weight and body weight gain was negative, and there was a loss of body weight in the individuals with a high FEC.

Variations in the length of the Y chromosome and the seminal attributes of Karan Fries bulls

Fresh semen and blood samples from 20 Karan Fries bulls (4-6 years of age), maintained at the Artificial Breeding Complex of the National Dairy Research Institute, Karnal, were collected for one year. All the bulls had 60 chromosomes, comprising 58 acrocentric autosomes and 2 sex chromosomes, with X as the larger and Y as the smaller submetacentric. The mean lengths of Yp and Yq; the total length of the Y chromosome and the length ratio were 1.10 +/- 0.01 microm, 1.83 +/- 0.02 microm, 2.92 +/- 0.02 microm and 62.46% +/- 0.18%, respectively. Analysis of the length measurements of the the Y chromosomes in Karan Fries bulls showed that all the measurements, viz., the short arm of the Y chromosome, the long arm of the Y chromosome, the total length of the Y chromosome and the variation in length of Y chromosome, varied significantly among bulls. All the seminal parameters, the volume of semen, mass activity, initial motility, concentration, live sperm count and the total abnormal sperm count, were significantly affected by bulls, whereas season had a significant effect on all the seminal parameters except the total abnormal sperm count. No significant relationship between the ratio of the long arm to the total length of the Y chromosome and seminal attributes was observed.