Filarial infection is resisted differentially by subjects having different blood group phenotypes.

This study was aimed to elucidate the relationship between major blood group antigens (BGAs) and susceptibility or resistance to human lymphatic filariasis. A total of 492 human subjects, living in Raipur city of Chhattisgarh, endemic for bancroftian filariasis in Central India, were screened for the presence of Wuchereria bancrofti microfilariae and disease manifestations. The frequency of BGAs was tabulated as a function of the status of filariasis, namely normal (no infection), mf carrier (presence of microfilariae in blood), and elephantiasis (confirmed clinical manifestations). The comparison of ABO phenotype distributions among all the three groups clearly indicated that disease status has a significant relationship with the blood group attributes. The result of chi2 analysis of the frequencies of ABO phenotypes observed in microfilaraemic and elephantiasis groups (observed frequency vs. expected frequency computed based on the distribution of the normal population) revealed that there has been a significant alteration in the distribution of ABO phenotypes in microfilaraemic, but not in elephantiasis, group. The susceptibility to filarial infection was computed as a function of blood group phenotypes in the population. The susceptibility and conditional susceptibility for elephantiasis were the least among the subjects with AB phenotypes. The mechanism of association between filariasis and ABO antigens needs to be further explored to understand how the distribution of BGAs affects susceptibility/resistance to infection.

Geometric phases for mixed states in interferometry.

We provide a physical prescription based on interferometry for introducing the total phase of a mixed state undergoing unitary evolution, which has been an elusive concept in the past. We define the parallel transport condition that provides a connection form for obtaining the geometric phase for mixed states. The expression for the geometric phase for mixed state reduces to well known formulas in the pure state case when a system undergoes noncyclic and unitary quantum evolution.

Impossibility of deleting an unknown quantum state.

A photon in an arbitrary polarization state cannot be cloned perfectly. But suppose that at our disposal we have several copies of a photon in an unknown state. Is it possible to delete the information content of one or more of these photons by a physical process? Specifically, if two photons are in the same initial polarization state, is there a mechanism that produces one photon in the same initial state and the other in some standard polarization state? If this could be done, then one would create a standard blank state onto which one could copy an unknown state approximately, by deterministic cloning or exactly, by probabilistic cloning. This could in principle be useful in quantum computation, where one could store new information in an already computed state by deleting the old information. Here we show, however, that the linearity of quantum theory does not allow us to delete a copy of an arbitrary quantum state perfectly. Though in a classical computer information can be deleted (reversibly) against a copy, the analogous task cannot be accomplished, even irreversibly, with quantum information.

Thermoregulatory spectrum in vertebrates.

Thermoregulatory mechanisms and control of homeothermy are quite recent from evolutionary stand point. Animals have either simply recruited or modified other regulatory systems for the purpose of thermoregulation. The degree of such recruitments or modifications vary among different class of vertebrates thus giving rise to a relative diversity in the spectrum of thermoregulatory control and mechanisms. The review briefly summarizes the evidence showing that body temperature control is not an isolated regulated system in vertebrates, rather, a hierarchically integrated multiple system. The available information shows that pineal transduces environmental cues for photoperiodic and seasonal adjustments to the preoptic area of anterior hypothalamus via its primary secretory product, melatonin. The hypothalamus integrates the information and then sets the effector recruitment for each control system consistent with the metabolic rate of the animal taking into considerations the cost and benefit of the action taken. The overwhelming similarity in response to different constituents of the thermoregulatory spectrum contradicts the aphorism that cold-blooded animals are dependent on ambient temperature. It is our collective view that there is no fundamental difference between ectotherms and endotherms since the two vary only in the degree of their ability to maintain thermal homeostasis.

The pineal gland: structural and functional diversity.

The article reviews the work carried out on pineal structure and function in vertebrates. The pineal has undergone striking changes in structure during the course of evolution from lamprey to mammals. In the primitive vertebrates, structure of the pineal is very much similar to that of the retina of the eyes and it acts as a direct photosensory organ. It acts as a photosensory and secretory organ in a number of species. Interestingly, the pineal complex among the reptiles presents the full spectrum of its morphological possibilities. There is a gradual regression of light sensitive pineal structure during the course of avian line of evolution. Further, it has been unequivocally accepted that mammalian pineal is an endocrine organ. The pineal is a prominent secretory organ, in mammals, which synthesises and secretes a number of exocrine and endocrine substances, such as indoles, peptides, various enzymes, amino acids and their derivatives, lipids, carbohydrates, and inorganic constituents. Pineal plays an important role in regulation of seasonal breeding in various vertebrate species. It is also considered as one of the most important components of the vertebrate circadian system and is a principal source of rhythmically produced melatonin. Apart from the above mentioned functions, pineal also influences thermoregulation, electrolyte metabolism, intermediary metabolism, hemopoiesis, immune system and behaviour.

Desynchronization of circadian rhythms in a group of shift working nurses: effects of pattern of shift rotation.

Sixteen shift working nurses, (eight senior and eight junior nurses) working in a Government hospital and five diurnally active healthy human subjects participated in the present study. The subjects self-measured oral temperature, heart rate, subjective fatigue, subjective drowsiness, finger counting speed and random number addition speed 4-6 times a day for about 3 weeks. Power spectrum and cosinor techniques were employed to analyze individual and group time series. The frequencies of circadian rhythm detection, by cosinor rhythmometry as a group phenomenon, were of 100%, 38%, and 21% in control subjects, senior nurses and junior nurses, respectively. These results were also complemented by power spectrum analysis. Desynchronization of circadian rhythms in several variables was documented in shift workers. The extent of desynchronization was more prominent among junior nurses as compared with their senior counterparts. It was also noticed that in several variables frequency multiplication of circadian rhythm took place among shift workers. The differences in terms of shift-work effects ranging from rhythm desynchronization to frequency multiplication between senior and junior nurses could be ascribed to the pattern of shift rotation employed.

Characteristics of circadian rhythm in six variables of morning active and evening active healthy human subjects.

Ten apparently healthy human subjects, inhabitants of dry and hot tropical climate, volunteered for the study. They were instructed to self-measure, several variables, such as oral temperature, heart rate, subjective fatigue, subjective drowsiness, finger counting speed and random number adding speed, daily, preferably at an interval of 4h, for 10-15 days. However, they were instructed to have ad libitum sleep and not to truncate sleep for the sake of self-measurements. The subjects were categorized into two groups, viz, morning active and evening active and their circadian time structure in the above mentioned variables was studied. The results clearly show a higher order of internal synchronization among all the variables. Comparison of acrophase locations between morning active and evening active individuals reveals that the peaks in oral temperature, heart rate and random number adding speed occurs earlier in morning active individuals (P < 0.002, P < 0.005, P < 0.001, respectively). The circadian profiles obtained in this study may serve as guide lines in the study of human health and diseases.

Age related modulation of circadian time structure of blood, plasma and tissue variables in male domestic fowls.

To study modulation of circadian time structure of 11 blood, plasma and tissue variables in male domestic fowls, as a function of age, three experiments were made in one-day-old fowls (72) standardized by 12L:12D. In the first experiment, at 6 week age, 24 birds were killed by decapitation, four each at six different circadian stages (2, 6, 10, 14, 18 and 22 hr after light onset, HALO). Equal number of birds were killed at similar circadian stages at the age of 12 and 18 week in the second and the third experiments, respectively. Age affected both, the circadian patterns and the mesors (24 hr mean values). The circadian pattern included amplitude (half of the total extent of variation) and acrophase (estimated time of peak) for each variable. The results clearly suggest that the pattern of circadian rhythm may vary as a function of age of the bird.

Late afternoon administration of melatonin is prosomatotrophic and exerts androgen independent effects on erythropoiesis in male house sparrow Passer domesticus.

In the third week of September 1989, birds were purchased locally and acclimated to their housing conditions in a room fully exposed to natural day length (average: 11.96 hr) and temperature (26 degrees +/- 2 degrees C) for 2 weeks. Birds were in the regressive phase of their annual gonadal cycle. In the first experiment 24 birds were selected randomly and were divided into 3 groups of 8 birds each. Initial body weight and bill color score were recorded. The birds of group-I and group-II were injected daily with 5 and 10 micrograms of melatonin in 0.1 ml of vehicle, respectively. The birds of group-III were injected with vehicle only and treated as control. Injections were given daily between 1700 and 1730 hrs over a period of 10 days. At the termination of the experiment, the birds were weighed, sacrificed, bill color scored, blood collected and immediately processed to determine the number of erythrocytes and hemoglobin concentration. The mean body weight loss amounted to 9.6% in vehicle-treated house sparrow. Birds receiving low and high doses of melatonin maintained their initial body weight. Melatonin significantly accelerated the rate of bleaching of bill color. Results clearly indicate that in house sparrow, melatonin produces prosomatotrophic and antigonadotrophic effects. The low dose of melatonin stimulated erythropoiesis significantly. In the second experiment, melatonin nullified the castration-induced decline in the number of circulating red cells. This clearly suggests that the influence of melatonin on erythropoietic machinery appears to be independent of testicular hormone(s).

Circadian features of carbohydrate metabolism in domestic fowls exposed to weekly 120 degree-shifts of synchronizer schedule.

Effects of weekly 8 hr advance- or delay-shifts on the circadian rhythm of plasma glucose, liver glycogen and muscle glycogen in male domestic fowls, beginning at about 3 days of age, were examined. Circadian rhythm in the aforesaid indices of carbohydrate metabolism in control birds was also studied. Blood and tissue samples were collected from birds in all the three groups at 4 hr intervals over a single 24 hr time scale both at 6th and 12th week of age. Plasma glucose and glycogen content in the tissues were determined by employing standard techniques. Cosinor rhythmometry was used for analyzing time series data. In general, a statistically significant circadian rhythm was documented for all the three indices in control and advance-schedule birds, irrespective of age. In contrast, in delay-schedule birds, statistically significant circadian rhythm could not be detected, excluding in muscle glycogen at 12th week of age. The poor growth rate in the delay-schedule birds could be imputed to the disappearance of circadian rhythm in the indices of carbohydrate metabolism.

Desynchronization of oral temperature, pulse and performance circadian rhythms in shift working Indian nurses.

Circadian time structure in shift working Indian nurses was studied. In shift workers desynchronization between circadian rhythms in different physiological variables was observed. Circadian amplitudes of oral temperature, pulse and random add speed rhythms decreased significantly in shift workers as compared to control subjects. Circadian mesors of performance rhythms increased significantly in shift workers indicating that the time taken by them was more for performing the tasks. It can be concluded that the subjects studied herein are intolerant to shift work and amplitude decrement may be considered as a chronobiologic index to determine the tolerance of individual workers to shift work.

Circadian time dependence of erythropoietic and respiratory responses of Indian garden lizard, Calotes versicolor, to mammalian urinary erythropoietin and thyroxine.

The circadian stage-dependent effects of mammalian urinary erythropoietin (Ep) and thyroxine (T4) on tissue energy metabolism (in vivo and in vitro) and erythropoiesis were examined in the Indian garden lizard. Both T4 and Ep increased erythropoiesis and also affected hepatic and muscle energy metabolism. Although both treatments increased circulating RBC count, irrespective of the timing of the treatment, the maximum erythropoietic stimulation was achieved only in the late photophase (9 hr after light onset, HALO). Hepatic oxygen uptake was significantly elevated at 3 and 9 HALO following in vivo Ep administration and 3, 9, and 15 HALO following in vivo T4 injection. In contrast, in vitro addition of either Ep or T4 to hepatic homogenates of untreated lizards significantly elevated respiratory rate, irrespective of the time of tissue collection. The rate of muscle tissue respiration was statistically elevated when Ep was administered in vivo at 9 and 15 HALO. The oxygen uptake was stimulated by T4 only at 15 HALO. While in vitro addition of Ep to tissue homogenates significantly depressed the respiratory rate of muscle collected at 3 HALO, addition of T4 stimulated oxygen uptake by the muscle tissue collected at 9 and 15 HALO. It is concluded that the effectiveness of Ep or T4 largely depends upon the phase of the organism's circadian system(s).

Effects of zeitgeber shifts on gonadal function in male domestic fowls.

Effects of shifting light dark (LD) schedule of 8 hr/week on comb height and gonadal development were investigated in male domestic fowls. Three-day-old birds were exposed to repeated delay (westward shift) or repeated advancement (eastward shift) of the LD schedule at weekly intervals till they attained the age of 20 weeks. Control birds were held in fixed LD 12:12 hr light/dark schedule. Comb height was monitored at weekly intervals beginning at the age of 7 weeks. At 12th, 16th and 20th week 5 birds from each schedule were sacrificed and gonadal volume was recorded. Results indicate that comb and gonadal growth were significantly higher in advance-schedule birds when compared with control and delay-schedule birds. Histologically, testes of advance-schedule birds were more active when compared with those of control and delay-schedule birds. It appears that the eastward shifts of the synchronizer schedule may exert stimulatory influence on gonads.

Influence of human urinary erythropoietin and L-thyroxine on blood morphology and energy reserves in two tropical species of fed and starved teleosts.

Erythropoietic responses of fed and starved species of teleosts, viz., Clarias batrachus and Heteropneustes fossilis, to human urinary erythropoietin and thyroxine have been examined. The effects of these hormones on energy reserves have also been evaluated. Twenty-four C. batrachus were divided into two groups: half were fed regularly; the remaining fish were starved 20 days. On the 21st day each group was further divided into three subgroups of four each and received either saline, thyroxine (8 micrograms), or erythropoietin (6 IU) over 4 consecutive days. The experimental protocol was identical for H. fossilis; however, for H. fossilis two identical studies were conducted approximately 1 year apart. A decline in the rate of erythropoiesis and a stimulatory response to human urinary erythropoietin followed starvation in both species of teleosts. In addition, erythropoietin had a pronounced effect on hepatic glycogenesis of fed H. fossilis and stimulated erythropoiesis in the fed teleosts of both species. Prolonged starvation drastically depleted hepatic glycogen in C. batrachus. In contrast, it had no effect on hepatic glycogen in H. fossilis and on muscle glycogen and protein in both species. In general, while both species could respond to erythropoietin and withstand prolonged starvation, H. fossilis alone exhibited remarkable tolerance to fasting.

Effects of repeated eastward and westward synchronizer phase-shifts on growth, blood morphology and biochemical variables in male domestic fowls.

The effects of repeated synchronizer phase-shifts on growth (increment in body weight), blood morphology and growth related biochemical variables in 3-day-old juvenile male chicks were evaluated till they become 20 weeks old. The control birds were kept under a fixed LD 12:12 light schedule throughout, while the LD 12:12 regimen of experimental birds was shifted weekly either by delaying (westward shift) or by advancing (eastward shift) the time of light onset by 8 hr. The rate of growth was more in fowls which were exposed to repeated advancement of synchronizer schedule than the controls and those exposed to westward shifts of the synchronizer schedule. Hematological indices, viz., hemoglobin concentration, number of circulating erythrocytes, hematocrit and biochemical variables, such as concentration of glucose and protein in plasma; glycogen, protein and lipid in liver; and muscle tissues were significantly more in chicks exposed to repeated eastward shifts, when compared with the control birds (LD 12:12). It is suggested that the eastward shift of the synchronizer may be beneficial for the poultry birds.

Time dependent effects of hormones on rate of protein synthesis in lymphoid organs of chickens.

Total protein content in blood serum and different lymphoid organs, such as bursa, spleen and thymus was investigated in chickens at two different circadian stages (0800 or 1600 hrs; early or late photophase) following administration of either saline or hormones (thyroxine or hydrocortisone or epinephrine). The results suggest that the lymphoid organs may respond differently to the exogenous administration of different hormones depending on the time of their administration.

Meal scheduling modulation of circadian rhythm of phototactic behaviour in cave dwelling fish.

Phototactic responses of three groups, each of 16 cave fishes, were observed at 4-hr intervals beginning at 0900, following 5 days of acclimation inside specially designed aquaria. The latter consisted of two parts, a photic zone and an aphotic zone. The first group of fishes were fed ad libitum, while the second and third group of fishes were fed with minced mutton and/or liver delivered in the photic zone between 0700-1100, and in the aphotic zone between 1900-2100. The percentage of fishes present in the photic zone at a given time was used as a measure of their phototactic responses. Single cosinor analysis of these data has revealed, for the first time, a circadian rhythmicity in the phototactic behaviour of a cavernicolous organism. However, imposition of restricted feeding schedules shifted the peak time of the circadian rhythm in phototactic responses. Meal scheduling may thus be an effective synchronizer for this behavioural rhythm.

Circannual rhythm in natural killer activity and mitogen responsiveness of murine splenocytes.

Seasonal variations were observed in murine splenic natural killer (NK) cell activity and also in murine lymphocyte responsiveness to mitogens, namely, concanavalin A, phytohemagglutinin, and lipopolysaccharide. The maximum and minimum splenic NK cell activities were observed in January-February and July-August, respectively. Conversely, maxima and minima of lymphoproliferative responses to all the three mitogens occurred in April-June and January-February, respectively. Such variations, when inferential statistics are used, appeared to be accounted for by circannual and other low-frequency (infradian) bioperiodicities. More specifically, the circannual rhythm in murine NK cell activity was demonstrated in data from a total of 356 mice collected over a period of 5 years. The various components of the immune system are characterized by a multifrequency time structure. The understanding of the organization of the immune system along the yearly scale may have bearings on that of the seasonal incidence of numerous infectious diseases and on the success/failure of immunotherapy.

Erythropoietin, testosterone, and thyroxine in the erythropoietic response of the snake, Xenochrophis piscator.

The erythropoietic response of snakes was examined after injecting human urinary erythropoietin (Ep), testosterone propionate (TP), and L-thyroxine (T4), separately and in combinations, into starved ophids. The effect of starvation was reflected by a decrease in the number of erythrocytes, a fall in hemoglobin concentration, and a decline in hematocrit. Statistically significant elevation of erythrocyte number, hemoglobin concentration, and hematocrit was observed at 24 hr following the administration of Ep + T4, and Ep + TP + T4 into starved ophids. The erythrocyte number was also increased by T4 treatment at 24 hr. Furthermore, while T4 and Ep individually increased the red blood cell number at 168 hr, T4, TP + T4, and Ep + TP + T4 elevated the hemoglobin concentration and Ep + T4 and Ep + TP + T4 increased the hematocrit value. It is suggested that the influence of any one of the hormones utilized in the present study on blood morphology of fasted snakes depends to a greater extent on the presence or absence of the other hormone(s).

Thyroid and gonad in the oxidative metabolism, erythropoiesis, and light response of the migratory redheaded bunting, Emberiza bruniceps.

In the thyroidectomized, adult male redheaded bunting exposed to a L/D cycle of 15/09, there were no significant changes in body weight, gonad size, respiratory rates of whole body, liver, muscle, red blood cell number, hemoglobin concentration, or hematocrit, unlike in intact birds. Further, while testosterone appeared as effective as L-T4 in determining body weight, gonadal size, and activity and oxygen uptake by skeletal muscle, it was of greater significance for kidney respiration and of secondary importance in its influence on blood morphology and respiratory rates of the liver and of the whole body of the bird.