Biomedical subjects
R D Martin
Publications and source records attributed to R D Martin.
Parentage analysis within a semi-free-ranging group of Barbary macaques Macaca sylvanus.
This study of a group of semi-free-ranging Barbary macaques Macaca sylvanus aimed to determine paternity, to establish whether any individual male achieved prominent mating success and to assess genetic variability. Analyses involved electrophoresis of 15 blood protein systems and multilocus DNA fingerprinting (isotopic and nonisotopic). Genetic variability was low; only two blood protein systems were polymorphic. Although all DNA-fingerprints were individual-specific, they showed a high average band-sharing index value (0.67). Nevertheless, a combination of all methods permitted inference of paternity in 11 out of 15 (73%) cases tested. Several males from different age classes fathered infants.
Diaspirin crosslinked hemoglobin (DCLHb) does not affect the anesthetic potency of isoflurane in rats.
Hemoglobin solutions are being developed as oxygen carrying fluids for multiple clinical indications. Despite an early report of accentuation of ether anesthesia, the effect of hemoglobin on anesthetic potency has not been assessed. We assessed the effect of alpha-alpha diaspirin crosslinked hemoglobin (DCLHb) on the anesthetic requirement of isoflurane necessary to keep rats unresponsive to noxious stimuli (1.0 MAC [minimum alveolar concentration]). During isoflurane administration, each rat received one of the following fluid regimens: 44Hct/N-normal hematocrit and volume; 44Hct/H-8.0 ml of donor blood given as a hypervolemic bolus; 30Hct/H-5.0 ml of DCLHb given as an exchange transfusion and 8.0 ml as a hypervolemic bolus; or 16Hct/H-15.0 ml of DCLHb given as an exchange transfusion and 8.0 ml as a hypervolemic bolus. MAC was determined using a standard tail clamp technique. The isoflurane requirement to achieve 1.0 MAC was not different between the four groups. These results are consistent with a hypothesis that DCLHb does not change the anesthetic state.
Primate palaeontology. Bonanza at Shanghuang.
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Nitrendipine and superoxide dismutase in ischemic renal injury.
The effect of the Ca entry blocker nitrendipine, the antioxidant superoxide dismutase (SOD), and a combination of nitrendipine and superoxide dismutase on postischemic renal function was studied in four groups (n = 24) of rats. The rats in group 1 (n = 6) were the ischemic control and received 10 mL of 0.9% NaCl. Group II (n = 6) received SOD 7.0 mg/kg. Group III (n = 6) received nitrendipine 1 mg/kg. Group IV (n = 6) received nitrendipine 1 mg/kg and SOD 7 mg/kg. After administration, both kidneys were rendered ischemic by cross-clamping the renal vessels for 60 min. Comparison of 24-h creatinine clearance (CCr) for 3 days after reversal of ischemia revealed: (a) nitrendipine alone was the most effective in preserving renal function (p < .05); (b) SOD provided some degree of improvement, but only on day 3 (p < .05); (c) a similar result was detected using a combination of nitrendipine and SOD (p < .05); (d) there was no significant difference between SOD and nitrendipine nor between SOD and the combination of nitrendipine/SOD; (e) there was a significant improvement with nitrendipine when compared to the combination of nitrendipine/SOD (p < .05).
Facial fractures.
Emergency room physicians frequently see facial fractures that can have serious consequences for patients if mismanaged. This article reviews the signs, symptoms, imaging techniques, and general modes of treatment of common facial fractures. It focuses on fractures of the mandible, zygomaticomaxillary region, orbital floor, and nose.
Primate origins: plugging the gaps.
Recent discoveries of fossil primate specimens have produced several surprises and challenged prevailing views of early primate evolution. Plesiadapiformes, long regarded as 'archaic primates', may perhaps be linked to the peculiar colugos instead. Inferred relationships of the earliest known undoubted primates (adapids and omomyids) are in turmoil. Both groups have been proposed as sources for the simian primates. Although the origin of the simian primates is obscure, new fossil evidence could push it further back by at least 10 million years. Such uncertainties reflect the low sampling level of the primate fossil record, which can potentially also lead to underestimation of times of origin within the primate tree.
Effects of sex steroids on maternal motivation in the common marmoset (Callithrix jacchus): development and application of an operant system with maternal reinforcement.
We developed an operant paradigm for measuring effects of reproductive steroids on maternal motivation in common marmosets (Callithrix jacchus). Conditioned response regulated females' exposure to maternal reinforcement. Nulliparous females (n = 15) with experience with infants in social groups were subjects. The paradigm was validated by examining (a) effects of reinforcing stimuli on affective behavior in a nonoperant paradigm, (b) responsiveness of operant performance to changes in reinforcing stimuli and reinforcement schedule, (c) changes in operant responding due to omission of reinforcement, and (d) relation between operant responding and species-typical maternal behavior. In pregnant females, (n = 4), frequency of bar pressing and estradiol:progesterone ratio were maximal just before birth. Nonpregnant females (n = 3) treated with progesterone and estradiol to mimic late-pregnancy steroid profiles showed increased operant maternal behavior.
The role of the bone-gallium scan in sternal osteomyelitis.
Sternal osteomyelitis is an uncommon but serious complication of the median sternotomy incision. Between 1982 and 1990, 160 patients with sternal osteomyelitis and wound dehiscence were treated with sternal debridement and pectoral muscle flap closure at The Toronto Hospital. Most of these wound infections were clinically obvious, and the need for surgical treatment apparent. In a small number of patients, however, the extent of the infection was more difficult to determine clinically. In this subset of patients, the interpretation of the bone-gallium scan was important in determining the presence or absence of bone infection and the probability of successful treatment without surgery. In this study, we review our findings at the time of surgery and compare them with the preoperative information available from the bone-gallium scan. The limited literature on this topic is reviewed. In this group of patients, we found the bone-gallium scan was not helpful in clinical management.
Sartorius myoplasty in the treatment of exposed arterial grafts.
The long-term success of sartorius myoplasty in 14 of 16 patients who presented with an exposed vascular graft in an infected groin is described. The presenting complications were wound dehiscence (ten patients), hemorrhage (two), skin erosion (two), late bilateral fistulas (one) and false aneurysm (one). Ten grafts were prosthetic and six autogenous. Positive cultures were obtained from 15 wounds; four grew Staphylococcus epidermidis, the remainder mixed or Gram-negative bacteria. Each groin was radically debrided, including the surface of the arterial graft, and, if possible, closed immediately with a sartorius myoplasty applied directly to the graft. Twist, fan and loop myoplasties were equally effective. Grossly infected wounds were debrided initially and obviously infected grafts were replaced in situ before myoplasty. Sartorius myoplasty is recommended as an elegant solution for the infected groin in which there is an exposed arterial graft.
Allometry and prediction in hominoids: a solution to the problem of intervening variables.
To avoid misinterpretation of allometric exponents determined from interspecific allometric comparisons, specific conditions must be met with respect to the common reference variable. Body weight is considered to be the best general indication of overall size and is hence widely acknowledged to be the most suitable reference variable. However, because of the paucity of recorded body weights for museum specimens, various comparative studies have used other size indicators as intervening variables, although the allometric relationships to body size/weight were often unknown and possibly differed between species. Because of differences in the scaling properties of alternative intervening variables across the species investigated, conflicting conclusions may be drawn if different variables are chosen as substitutes for overall size. This is illustrated with two examples. In this study, series of skeletons with associated body weights of Gorilla, Pan, Pongo, and Homo were investigated. Both ontogenetic and static adult allometric relationships between several widely used reference variables and body weight were determined. Neither these variables nor additional estimators investigated in this study displayed allometric exponents and coefficients similar enough across species to justify direct interspecific comparison. To generate an alternative size estimator for both ontogenetic and static interspecific investigations, equations for combined sexes were derived to predict body weight from various long bone dimensions for individual hominoid species. From a total of 25 predictors, 12 prediction equations per species (six for nonadults and six for adults) were selected according to their relative suitability for reliable prediction of body weight. It is shown that the derived reference variable "predicted body weight" avoids problems of intervening variables, is valid for any interspecific ontogenetic and static allometric comparison, and displays less fluctuation in comparison to actual body weight.
Palaeontology. New fossils and primate origins.
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Sartorius myoplasty for deep groin wounds following vascular reconstruction.
Groin wound infections following vascular reconstructive surgery prolong hospital admission and convalescence and may lead to more serious morbidity with prosthetic graft infection, false aneurysm formation, or hemorrhage. Therefore, it is imperative to achieve wound closure as expeditiously as possible. Herein, we describe 11 patients with complicated groin wounds and report our management using sartorius myoplasty. Five of these patients had underlying prosthetic grafts at risk. All patients underwent wound closure with sartorius myoplasty after adequate debridement of necrotic and infected soft tissue. Success of wound closure with complete primary healing was observed in nine patients, while in two, adequate early coverage of femoral vessels was achieved, but extended wound care for superficial skin separation was necessary with eventual complete healing. There was no morbidity or mortality related to the added surgical procedure. One patient underwent late repair of a femoral false aneurysm. There were no other complications seen after an average follow-up of 20 months (range: 6 to 49 months). In summary, we recommend that sartorius myoplasty be considered for wound infections to hasten groin closure, decrease hospital stay, and reduce the chance of infectious complications.
Effect of calcium entry blocker nitrendipine on renal function after renal vascular occlusion.
The ability of the Ca entry blocker nitrendipine to improve postischemic renal function was studied in nine groups (n = 70) of rats. After anesthesia, nitrendipine was administered for 15 min through the femoral vein. The dose administered depended on the group. Group 1 (n = 7), the control, received only 0.9% NaCl, group 2 (n = 12) 0.25 mg/kg; group 3 (n = 10) 0.50 mg/kg; group 4 (n = 8) 0.75 mg/kg; group 5 (n = 6) 1.00 mg/kg; group 6 (n = 7) 1.50 mg/kg; group 7 (n = 7) 2.00 mg/kg; group 8 (n = 6) 2.50 mg/kg; and group 9 (n = 7) 3.00 mg/kg. After the administration of nitrendipine, the kidneys were rendered ischemic for one hour by cross-clamping the renal vessels. Comparison of 24-h creatinine clearances for 72 h after reversal of ischemia demonstrated that nitrendipine was capable of providing a degree of protection against renal ischemia and the protective effect was dose dependent (p less than .05).
Urinary endocrine monitoring of the ovarian cycle and pregnancy in Goeldi's monkey (Callimico goeldii).
A non-invasive study of urinary hormones in 6 captive female Goeldi's monkeys provided accurate information on reproductive function. Conjugated oestrone accounted for 80-85% of the urinary oestrone and oestradiol measured. Radioimmunoassay measurements of conjugated oestrone provided a reliable indicator of cyclic ovarian function (mean cycle length: 24.1 +/- 0.9 days; n = 9) and pregnancy (gestation: 145, 155 days; n = 2). Measurements of urinary progesterone and pregnanediol glucuronide were only reliable as indicators of ovarian cyclicity. Elevations in urinary conjugated oestrone coincided with luteal-phase elevations of urinary progesterone and pregnanediol glucuronide. Urinary LH concentrations provided no indication of pituitary activity. However, the frequencies of female sexual solicitations of males were maximal when oestrone conjugate concentrations rose, suggesting a peri-ovulatory period. Ovulation was suppressed in 1 of 3 subordinate females housed in male-female-female trios.
Anesthesia for cardiac transplantation.
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Anesthetic management of neonatal cardiac transplantation.
Anesthetic management of thirteen neonatal heart transplant patients is reviewed. Donor management, preoperative, operative and early postoperative management is discussed. Ten of 13 patients in this series survived the operation and appear to be developing normally.
The management of infected median sternotomy wounds.
Extensive experience with infected sternotomy wounds treated by aggressive debridement and immediate, laterally based pectoralis muscle flaps has shown this to be a reliable and effective treatment for a major complication previously associated with high morbidity and mortality. This is a plastic surgery operation that saves lives and health care dollars.