Trees before and after Darwin

Phylogenetic trees published before Darwin’s On the Origin of Species are scarce. Lamarck (1809) and Barbançois (1816; J Phys Chim Hist Nat Arts 82, 444) are the first and only trees devoted to illustrating the genealogical connections between organisms of different species and different higher taxa. In the late 18th and early 19th centuries, most of the trees depicted in papers dealing with natural history were classifications; classifications in the shape of trees, but classifications nonetheless. Those published by Bronn (1858) are a good example. After Darwin, phylogenetic trees incorporating the time dimension flourished. In the first half of the 20th century, the Modern Synthesis failed to renew and rejuvenate the intuitive construction of trees. It wasn’t until the appearance of Hennig’s phylogenetic systematics that the real nature of the connection between phylogeny and the pre‐Darwinian concept of homology was made clear.     

Pair-association in twin lambs before and after weaning

Association between twin lambs before and after weaning and their association with their dam before weaning was observed in Dalesbred, Jacob, Border Leicester and Border Leicester × Jacob Lambs. There was no significant difference between breeds, but the females spent more time close to the ewe than the males. The proportion of close associations was less and intermediate associations were higher in twins of mixed sex. The major effect of weaning was an increase in pair-association for 2 days; by the third day, pairassociation had returned to pre-weaning levels. It is interesting that pair-association with non-castrated males increased after weaning.     

Motility patterns in mouse spermatozoa before and after capacitation

The motility patterns of mouse spermatozoa before and after capacitation are described. The latter is very characteristic, with spermatozoa describing a figure-8 pattern while remaining relatively stationary within a 3-dimensional space.     

Rectal temperatures before and after parturition in bottlenose dolphins

In five parturitions of four bottlenose dolphins (Tursiops truncatus gilli), rectal temperatures (Rts) were determined at least once a day during the late period of pregnancy. Four of the five pregnancies showed a drop in RT ranging from 0.7 to 1.3°C (an average decrease of 0.9°C) from 24 to 12 hr pre‐partum. In these four cases, RT was significantly lower than their averages from 10 days to 1 day pre‐partum (P < 0.05). In two dolphins, the first RT post‐partum was higher than the average RT from 10 days to 1 day pre‐partum. Seasonal changes in RT were observed in six non‐pregnant dolphins. Average RT in June through August was significantly higher and in December through February was significantly lower than the rest of the year (P < 0.01). Zoo Biol 18:153–156, 1999. © 1999 Wiley‐Liss, Inc.     

Cytogenetic studies in leprosy patients before and after chemotherapy

Summary The frequencies of chromosome aberrations and sister chromatid exchanges (SCEs), cell proliferation kinetics and mitotic indices were studied in peripheral blood lymphocyte cultures of leprosy patients both before and after chemotherapy. The differences in the frequencies of chromosome aberrations and SCEs between controls, paucibacillary and multibacillary patients were found to be statistically highly significant (P < 0.001). The extent of cytogenetic damage seemed to depend on the severity of the disease. Lymphocytes of untreated leprosy patients showed a low mitotic index and a slow rate of cell proliferation. Following combined treatment with dapsone and rifampicin there was an increase, but to a lesser degree (P < 0.01), in the frequency of SCEs and chromosome aberrations while the drug combination of dapsone, rifampicin and clofazamine had a non-mutagenic effect on chromosomes of the patient. Furthermore, after drug treatment, the cell proliferation rate and mitotic indices in paucibacillary patients were comparable to that of controls. These results indicate the clastogenic potency of Mycobacterium leprae and the remedial effects that follow therapeutic drug treatment.     

Anti-trichomonal IgA antibodies in trichomoniasis before and after treatment

Anti-trichomonal IgA antibodies were estimated by enzyme-linked immunosorbent assay (ELISA) in serum and vaginal secretions of 25 symptomatic and 25 asymptomaticTrichomonas vaginalis positive patients before and after treatment and in 25 age-matched controls. Significantly higher levels of antitrichomonad IgA antibodies were found inT. vaginalis positive patients when compared to control subjects, especially in vaginal secretions. In addition, a significant decrease in these antibodies was observed after treatment, which was more pronounced in vaginal secretions. It seems that anti-trichomonal IgA antibodies in serum and more so in vaginal secretions are directly related to and specific to the presence ofT. vaginalis in the urogenital tract.     

Blood volume determinations in sheep before and after splenectomy

Using 51Cr labelled RBCs, total blood volume, red cell volume and plasma volume were measured in fifteen adult, female, domestic sheep both before and after splenectomy. Eight of the fifteen animals studied were anemic. Statistical analyses revealed no significant differences in blood volume parameters whether animals were grouped together or separated into normal and anemic groups. We observed: (a) splenectomy produced modest reductions in blood volume parameters in 12 of 15 animals, (b) preoperative variability in blood volume parameters caused by release of sequestered RBCs from the spleen was eliminated after splenectomy, and (c) equilibration of 51Cr required at least 30 minutes in intact animals, but only 10 minutes in splenectomized animals. After volume parameters were normalized to body weight, they were found to agree closely with values reported previously. This study demonstrates the dynamic function of the sheep spleen in the regulation of blood volume.     

Phosphatase activities in rat liver before and after birth

Synopsis Several phosphatase enzymes have been studied biochemically and cytochemically to ascertain whether there are ontogenic changes in level or location. Nucleoside monophosphatase (5-nucleotidase) and lysosomal acid phosphatase are low in foetal liver and, unlike glucose-6-phosphatase, are still quite low in neonatal liver. Bile canaliculi show strong staining for 5-nucleotidase in adult liver but not in foetal or neonatal liver. Nucleoside diand triphosphatase activities in foetal liver are already near half the adult level. The diphosphatase that is active towards UDP shows the same cytochemical locations in neonatal liver as in adult liver. Triphosphatase activity in foetal and neonatal liver is located largely in star-like cells, rather than in the bile canaliculi of parenchymal cells. Biochemical comparison of foetal, neonatal and adult liver has shown that inorganic pyrophosphatase (assayed without Mg²⁺) parallels glucose-6-phosphatase, but acid ribonuclease does not parallel acid phosphatase. In albino rats injected with thyroxine, glucose-6-phosphatase has shown a more marked increase in foetal liver than in adult liver, although the uptake of thyroxine seemed to be less. In hooded rats, foetal liver showed a negligible uptake of thyroxine and no rise in glucose-6-phosphatase.A. A. El-Aaser is on leave from the Faculty of Medicine, University of Cairo.     

Mammographic measurements before and after augmentation mammaplasty

Thirty-five augmented women underwent mammography using both the standard implant-compression technique and, when possible, the implant-displacement technique; all had preaugmentation film-screen mammography available for evaluation. The area of mammographically visualized breast tissue before and after augmentation mammaplasty was measured using a transparent grid. Patients with subglandular implants had a mean decrease of 49 percent of measurable tissue area with compression mammography and a 39 percent decrease with displacement mammography. Patients with submuscular implants had a 28 percent decrease in measurable tissue area with compression mammography and a 9 percent decrease with displacement mammography. Anterior breast tissue was seen better with displacement mammography; posterior breast tissue, with compression mammography. Most patients had some degree of parenchymal scarring and lower image quality after augmentation. State-of-the-art mammography was not possible in most patients augmented with silicone-gel-filled implants.     

Intraoperative Electroretinograms before and after Core Vitrectomy

Purpose

To evaluate retinal function by intraoperative electroretinograms (ERGs) before and after core vitrectomy.

Design

Retrospective consecutive case series.

Method

Full-field photopic ERGs were recorded prior to the beginning and just after core vitrectomy using a sterilized contact lens electrode in 20 eyes that underwent non-complicated vitreous surgery. A light-emitted diode was embedded into the contact lens, and a stimulus of 150 ms on and 350 ms off at 2 Hz was delivered. The amplitudes and latencies of the a-, b-, and d-waves, photopic negative response (PhNR), and oscillatory potentials (OPs) were analyzed. The intraocular temperature at the mid-vitreous was measured at the beginning and just after the surgery with a thermoprobe.

Results

The intraocular temperature was 33.2 ± 1.3°C before and 29.4 ± 1.7°C after the vitrectomy. The amplitudes of the PhNR and OPs were significantly smaller after surgery, and the latencies of all components were prolonged after the surgery. These changes were not significantly correlated with the changes of the temperature.

Conclusion

Retinal function is reduced just after core vitrectomy in conjunction with significant temperature reduction. The differences in the degree of alterations of each ERG component suggests different sensitivity of each type of retinal neuron.     

Middle-ear dynamics before and after ossicular replacement

The mechanism of hearing involves conduction of mechanical vibrations along the ossicular chain to the inner ear. An acoustic wave is collected and transformed as it passes down the ear canal and impacts on the tympanic membrane (ear drum). The drum is connected to the inner-ear by three ossicle bones (malleus, incus, and stapes) in a complex arrangement, which serves to further transform the mechanical vibration before it reaches the cochlea of the inner ear. What is the mechanical function of the ossicular chain, and what are the biomechanical consequences of surgical reconstruction with prostheses? To answer these questions, a three-dimensional finite element model of the outer ear canal and middle ear was generated. The dynamical behaviour was predicted for the normal ear, and an ear reconstructed with partial and total ossicular replacement prostheses. For the normal ear, stapes amplitudes of 1x10(-8) m at low frequencies decrease to 4x10(-10)m at approximately 3kHz with several resonance peeks in between, most significantly at approximately 1kHz. Thereafter a further resonance is predicted at 4kHz associated with the ear canal. The behaviour is changed fundamentally by adding a prosthesis; the partial replacement increases the vibratory coupling of the drum and the stapes compared to the normal ear whereas the total replacement does the opposite, and is predicted to have the disadvantage of bringing several new resonances of the ossicular chain into the hearing range. It is hypothesised that the function of the malleus-incus-stapes arrangement is to link the drum to the oval window with the flexibility required for impedance matching but the rigidity to prevent unconstrainable resonances from occurring in the hearing range. If this is true, then the structural stiffness of ossicular chain is the critical design variable for middle-ear replacement prostheses.     

Ischaemia-modified albumin levels in newborn jaundice before and after phototherapy

The aim of our study was to assess the effect of phototherapy (PT) on ischaemia‐modified albumin (IMA) and malondialdehyde (MDA) levels in hyperbilirubinemic full‐term newborns. The study was performed on 36 full‐term infants exposed to PT. The babies were aged 3 to 13 days. IMA and MDA levels of the babies were determined before and after PT, by a colorimetric assay. IMA levels before and after PT were found as 0.424 ± 0.290 and 0.531 ± 0.262 absorbance units, respectively. Although IMA levels after PT were slightly higher, the difference was not statistically significant (p > 0.131). MDA levels before and after PT were found as 8.4 ± 1.8 µmol/l and 9.4 ± 1.5 µmol/l, respectively. Serum MDA concentrations were significantly higher after PT than before PT (p < 0.000). In previous studies, conflicting findings have been reported about the effect of PT on oxidant and antioxidant systems. However, we have found no study investigating IMA levels in hyperbilirubinaemia in newborns before and after PT. Our results shows that PT does not affect IMA levels significantly. IMA increases as a result of oxidative stress. We believe that the lack of significant difference between our IMA levels before and after PT may resulted from hyperbilirubinaemia, which has antioxidant effect. Copyright © 2011 John Wiley & Sons, Ltd.