Showing papers by "University of Texas Medical Branch published in 1988"

Neuropsychiatric Disorders Caused by Cobalamin Deficiency in the Absence of Anemia or Macrocytosis

Abstract: Among 141 consecutive patients with neuro-psychiatric abnormalities due to cobalamin deficiency, we found that 40 (28 percent) had no anemia or macrocytosis. The hematocrit was normal in 34, the mean cell volume was normal in 25, and both tests were normal in 19. Characteristic features in such patients included paresthesia, sensory loss, ataxia, dementia, and psychiatric disorders; longstanding neurologic symptoms without anemia; normal white-cell and platelet counts and serum bilirubin and lactate dehydrogenase levels; and markedly elevated serum concentrations of methylmalonic acid and total homocysteine. Serum cobalamin levels were above 150 pmol per liter (200 pg per milliliter) in 2 patients, between 75 and 150 pmol per liter (100 and 200 pg per milliliter) in 16, and below 75 pmol per liter (100 pg per milliliter) in only 22. Except for one patient who died during the first week of treatment, every patient in this group benefited from cobalamin therapy. Responses included improvement in neuropsychiatric abnormalities (39 of 39), improvement (often within the normal range) in one or more hematologic findings (36 of 39), and a decrease of more than 50 percent in levels of serum methylmalonic acid, total homocysteine, or both (31 of 31). We conclude that neuropsychiatric disorders due to cobalamin deficiency occur commonly in the absence of anemia or an elevated mean cell volume and that measurements of serum methylmalonic acid and total homocysteine both before and after treatment are useful in the diagnosis of these patients.

High-dose barbiturate control of elevated intracranial pressure in patients with severe head injury

Abstract: ✓ In a five-center study, 73 patients with severe head injury and elevated intracranial pressure (ICP) were randomly assigned to receive either a regimen that included high-dose pentobarbital or one that was otherwise similar but did not include pentobarbital The results indicated a 2:1 benefit for those treated with the drug with regard to ICP control When patients were stratified by prerandomization cardiac complications, the advantage increased to 4:1 A multiple logistic model considering treatment and selected baseline variables indicated a significant positive treatment effect of barbiturates, a significant effect of time from injury to randomization, and an interaction of treatment with cardiovascular complications However, of 925 patients potentially eligible for randomization, only 12% met ICP randomization criteria The results support the hypothesis that high-dose pentobarbital is an effective adjunctive therapy, but that it is indicated in only a small subset of patients with severe head in

Validity and Reliability of Self Report Measures of Physical Activity: An Information-Processing Perspective

Abstract: The published data on the reliability of self report measures of physical activity most commonly used in the cardiovascular disease epidemiology literature revealed high test-retest reliability coefficients for two of the measures, and modest to nonexistent intertest correlations Validity coefficients were low to modest The published data on the accuracy of the self report measures, however, revealed memory decay, memory of rare events alone, and lack of motivation in memory recall An information processing model, composed of encoding, storage, and retrieval processes is proposed to understand the memory of physical activity, and to identify necessary skills for accurate self report identified at each step in the process Questions requiring further research to specify this model and, in turn, improve accuracy of recall, are raised

Adaptive Coloration in Young Cuttlefish (Sepia Officinalis L.): The Morphology and Development of Body Patterns and Their Relation to Behaviour

Abstract: Young Sepia officinalis (0-5 months) were studied in the laboratory and in the sea, and their appearance and behaviour compared with that of adult animals Cuttlefish lay large eggs and the hatchlings are miniature replicas of the adults From the moment of hatching they show body patterns as complex as those of adults and far more elaborate than those shown by most juvenile cephalopods There are 13 body patterns: 6 of these are \`chronic' (lasting for minutes or hours) and 7 are \`acute' (lasting for seconds or minutes) The patterns are built up from no fewer than 34 chromatic, 6 textural, 8 postural and 6 locomotor components, used in varying combinations and intensities of expression Nearly all these components occur in young animals: 26 of the chromatic, all the textural and locomotor, and 6 of the postural components Nevertheless, patterning does change with age and we have recorded this and correlated the changes with behaviour The components are built up from units, which themselves comprise four elements organized in precise relation to one another: chromatophores, iridophores, leucophores and skin muscles The chromatophores are always especially important: they are muscular organs innervated directly from the brain and controlled ultimately by the highest centres (optic lobes) The areas in the Sepia brain that control patterning are already well developed at hatching, for the appearance of the skin is as much part of the brain's motor program as is the attitude of the arms or fins, or the posture of the entire animal The iridophores and leucophores develop later and are especially important constituents of many adult patterns, notably the Intense Zebra of the mature male Experiments confirm that patterning is neurally controlled and apparently mediated exclusively by the visual system Young cuttlefish use patterning primarily for concealment, utilizing such strategies as general colour resemblance, disruptive coloration, obliterative shading, shadow elimination, disguise and adaptive behaviour Older animals also conceal themselves but increasingly use patterns for signalling, both interspecifically (warning or `deimatic' displays) and intraspecifically (sexual signalling) Laboratory-reared cuttlefish were released in the sea and observed underwater They quickly and effectively concealed themselves on the substrate; it was easy for the human observer to lose them and many passing fish behaved as if they were not there One local predator, Serranus cabrilla, was observed to attack them and no fewer than 35 attacks were recorded, only six of which were successful Laboratory-reared cuttlefish apparently distinguished between these predators and other, non-predatory, fish the first time they encountered them in nature

Bacteriologic diagnosis of nosocomial pneumonia following prolonged mechanical ventilation.

Abstract: Cultures of tracheal secretions, bronchoalveolar lavage (BAL), protected specimen brushes (PSB), and direct lung aspirates were compared with cultures of lung homogenates and histologic findings in 35 baboons after 7 to 10 days of intubation and mechanical ventilation. Six animals received no antibiotics, while the remainder were treated with a variety of prophylactic regimens of intravenous and topical agents. Bacterial contamination at each culture site was expressed as a “bacterial index” (BI), obtained as the sum of the logarithmic concentrations of individual species. In the absence of antibiotics, pneumonias occurred in all animals and were polymicrobial; 56% of organisms in lung tissue were members of the normal upper respiratory tract flora, while 44% were gram-negative bacilli with a mean total bacterial index of 13.94/g. Lobar tissue BI values > 6.0/g were found in 77% of lobes containing pneumonias judged by histologic criteria to be moderate or severe in extent, whereas only 7% of lobes with l...

6 Yolk Absorption in Embryonic and Larval Fishes

Abstract: Publisher Summary This chapter discusses the yolk absorption in embryonic and larval fishes. The rate and efficiency of yolk absorption are influenced by a number of environmental factors, including temperature, light, oxygen concentration, and salinity. Fish eggs are not motile, and thus developing embryos are unable to actively exploit the most favorable environments available, at least until after hatching. In teleost eggs, the yolk syncytium together with overlaying mesoderm and ectoderm spreads to enclose the entire yolk mass. Endoderm does not follow the movement of the teleost blastodisc rim and, consequently, the yolk is not enclosed by an endodermal layer. Yolk platelets are mobilized more rapidly than the oil globule from the yolk mass, especially after hatching. The rate at which yolk reserves are depleted must be a function of the surface area of the absorptive layer and the metabolic activity of that layer.

Mechanism of muscarinic receptor-induced K+ channel activation as revealed by hydrolysis-resistant GTP analogues.

Abstract: The role of a guanine nucleotide-binding protein (Gk) in the coupling between muscarinic receptor activation and opening of an inwardly rectifying K+ channel [IK(M)] was examined in cardiac atrial myocytes, using hydrolysis-resistant GTP analogues. In the absence of muscarinic agonist, GTP analogues produced a membrane current characteristic of IK(M). The initial rate of appearance of this receptor-independent IK(M) was measured for the various analogues in order to explore the kinetic properties of IK(M) activation. We found that IK(M) activation is controlled solely by the intracellular analogue/GTP ratio and not by the absolute concentrations of the nucleotides. Analogues competed with GTP for binding to Gk with the following relative affinities: GTP gamma S greater than GTP greater than GppNHp greater than GppCH2p. At sufficiently high intracellular concentrations, however, all GTP analogues produced the same rate of IK(M) activation. This analogue-independent limiting rate is likely to correspond to the rate of GDP release from inactive, GDP-bound Gk. Muscarinic receptor stimulation by nanomolar concentrations of acetylcholine (ACh), which do not elicit IK(M) under control conditions, catalyzed IK(M) activation in the presence of GTP analogues. The rate of Gk activation by ACh (kACh) was found to be described by the simple relationship kACh = 8.4 X 10(8) min-1 M-1.[ACh] + 0.44 min-1, the first term of which presumably reflects the agonist-catalyzed rate of GDP release from the Gk.GDP complex, while the second term corresponds to the basal rate of receptor-independent GDP release. Combined with the estimated K0.5 of the IK(M)-[ACh] dose-effect relationship, 160 nM, this result also allowed us to estimate the rate of Gk.GTP hydrolysis, kcat, to be near 135 min-1. These results provide, for the first time, a quantitative description of the salient features of G-protein function in vivo.

Anatomy and physiology of descending control of nociceptive responses of dorsal horn neurons: comprehensive review.

Abstract: Publisher Summary This chapter discusses the anatomy and physiology of descending control of nociceptive responses of dorsal horn neurons. Sensory pathways in vertebrates are controlled by descending pathways originating in the central nervous system and projecting to the brain stem and spinal cord or even peripherally to sense organs. The operation of the analgesia systems involves inhibition of neurons in the pathways that process nociceptive information. The delineation of neural systems that control nociceptive transmission in the spinal cord is an active field. There are descending excitatory pathways that enhance sensory transmission, presumably including pain. These contribute to the mechanism of pain states resulting from the activity of central neurons. More effort is needed in several areas, including detailed studies of the neural circuits responsible for spinal cord processing of descending commands, assessment of the roles of pre- and postsynaptic inhibition, assignment of the effects of stimulation in different brain stem areas to particular pathways, and analysis of the neurotransmitters used in the various control systems.

Effect of Nasal Airway Positive Pressure on Upper Airway Size and Configuration

Abstract: The effect of nasal airway positive pressure (NAPP) on upper airway size and configuration during wakefulness was studied by computerized tomography in 12 obese subjects with obstructive sleep apnea (OSA), seven weight- and age-matched subjects without OSA, and 12 normal subjects. NAPP of 10 to 12 cm H2O was associated with a significant increase in airway area throughout the upper airway in all three groups. The change in airway area per cm H2O NAPP increased from nasopharynx to hypopharynx. The change in airway area per cm H2O NAPP was significantly smaller in the OSA than in the normal subjects in the region of the soft palate. Electromyographic recordings of the genioglossus and alae nasi muscles with and without NAPP during wakefulness in five of the OSA and five of the normal subjects showed either a decrease or no change in phasic and tonic activity with NAPP. In a separate series of experiments in an additional five OSA and five normal subjects, NAPP of zero, 5, 10, and 15 cm H2O was associated wi...

Acculturation and alcohol consumption among Mexican Americans: a three-generation study.

Abstract: Data from a three-generation study of Mexican Americans conducted in the San Antonio, Texas area are utilized to examine the influence of acculturation into the larger society on alcohol consumption. Acculturation was not related to alcohol consumption in the older generation. In the middle generation, it was related to lower alcohol consumption among men, as well as among women. In the younger generation, acculturation was related to more drinking among women, but not among men. Within-family analysis showed that the alcohol consumption of members of the younger generation was associated with the consumption of their parents, particularly in the case of younger women.

Speech acts and the pragmatic deficits of autism

Abstract: In a videotaped free-play session with a parent, autistic children were compared with mental-age matched Developmental Language Delay (DLD) children and with normally developing (ND) 2-year-olds in...

Effect of propranolol administration on hemodynamic and metabolic responses of burned pediatric patients.

Abstract: Hypermetabolism, increased heart rate, and lipolysis are responses to high catecholamine levels associated with burn injury. This study tests the hypothesis that adrenergic beta blockade in burns could reduce myocardial work, lipolysis, and negative nitrogen balance without adversely affecting cardiac or metabolic function. Eighteen patients with burns of 70 +/- 3% total burn surface area (TBSA) (Mean +/- SEM), were studied after a 5-day infusion of 2 mg/Kg of intravenous (I.V.) propranolol infusion every 24 hours without their cardiac output or resting energy expenditure being adversely reduced. Heart rate, left ventricular work, and rate pressure product were significantly reduced by 20, 22, and 36%, respectively (P less than 0.05). Plasma glucose, free fatty acids, triglycerides, and insulin levels remained unchanged. The rate of urea production, however, was significantly increased by 54 +/- 12% in fasted patients, and to a much lesser 12 +/- 2% in fed patients. The marked decrease in myocardial work afforded by propranolol administration may be of clinical benefit in the treatment of large burns. Variations in drug dosage and feeding regimens will, however, need to be perfected to limit catabolic effects.

Effect of temperature on laboratory growth, reproduction and life span of Octopus bimaculoides

Abstract: Laboratory culture of 40 Octopus bimaculoides from April 1982 to August 1983 through the full life cycle at 18°C vs 23°C provided information on the growth, reproductive biology and life span of this California littoral octopus. At 18°C, the cephalopods grew from a hatchling size of 0.07 g to a mean of 619 g in 404 d; the largest individual was 872 g. Octopuses cultured at 23°C reached their highest mean weight of 597 g in 370 d; the largest individual grown at this temperature was 848 g after 404 d. Growth data revealed a two-phase growth pattern: a 5 mo exponential phase followed by a slower logarithmic (power function) phase until spawning. At 5 mo octopuses grown at 23°C were over three times larger than their 18°C siblings. However, beyond 6.5 mo, growth rates were no higher at 23°C than at 18°C. At 13.5 mo, the mean weight of the 18°C group surpassed that of the 23°C group. The slope of the length/weight (L/W) relationship was significantly different for the two temperature regimes, with the 23°C octopuses weighing 18% less than their 18°C siblings at a mantle length of 100 mm. Females weighed more than males at any given mantle length. Males grew slightly larger and matured before females. The L/W relationship indicated isometric body growth throughout the life cycle. Higher temperature accelerated all aspects of reproductive biology and shortened life span by as much as 20% (from approximately 16 to 13 mo). O. bimaculoides has one of the longest life cycles among species with large eggs and benthic hatchlings. Extrapolations to field growth are made, and the possible effects of temperature anomalies such as El Nino are discussed.

Communication behaviors in autism and developmental language delay.

Abstract: – The communicative behavior of autistic and developmental language delay (DLD) children matched for nonverbal mental age and mean length of utterance (MLU) was compared to that of normally-developing (ND) 2-yr-olds. Autistic children were less able than other children to respond correctly to language or gestures used to direct their attention, used attention directing (pointing, showing) less frequently, and produced more echolalic speech when making requests. DLD and ND children differed only in number of pronouns used while requesting. Attention-directing gestures were associated with receptive and expressive language abilities for autistic, DLD and normal children.

Operative drainage of the pancreatic duct delays functional impairment in patients with chronic pancreatitis. A prospective analysis.

Abstract: In a prospective study, 85 patients with chronic pancreatitis have been subjected to evaluation by morphologic analysis (endoscopic retrograde cholangiopancreatography), by exocrine function tests (bentiromide PABA and 72-hour fecal fat testing), and by endocrine function tests (oral glucose tolerance test and fat-stimulated release of pancreatic polypeptide). All patients were graded on a five-point system, with 1 point assessed for an abnormal result in each of the five tests performed. Zero score denoted mild disease; 1-2 points signaled moderate disease; and 3-5 points indicated severe disease. In 68 patients, both an initial and late (mean follow-up period of 14 months) evaluation were performed. Forty-one patients underwent modified Puestow side-to-side Roux-en-Y pancreaticojejunostomy. The Puestow procedure alone was performed in 18 patients. Eight patients also had drainage of pseudocysts, seven also had a biliary bypass, and eight had pseudocyst drainage plus bypass, in addition to the Puestow. There were no deaths. Of the 68 patients who were studied twice, 30 had operations and 38 did not. None of the patients with severe disease improved their grade during follow-up. Of 24 patients who did not undergo operation, 17 (71%) who were graded mild/moderate progressed to a severe grade at follow-up. By contrast, only three of the 19 patients operated on (16%) and who were initially graded as mild/moderate progressed to severe disease at follow-up testing. More than 75% of all of the patients had a history of weight loss. Twenty-six of 30 patients operated on (87%) (all of whom had lost weight before surgery) gained a mean 4.2 kg (range 1.4-2.7 kg) after surgery, compared with no significant weight change (range -3.6-2.7 kg) among patients not operated on. These findings support a policy of early operation for chronic pancreatitis, perhaps even in the absence of disabling abdominal pain.

Relationship of depth of brain lesions to consciousness and outcome after closed head injury

Abstract: ✓ Magnetic resonance (MR) imaging was performed in 94 patients who sustained closed head injury of varying severity. Results of MR studies obtained after the intensive care phase of treatment disclosed that intracranial lesions were present in about 88% of the patients. Consistent with the centripetal model of progressive brain injury proposed in 1974 by Ommaya and Gennarelli, the depth of brain lesion was positively related to the degree and duration of impaired consciousness. Further analysis indicated that the relationship between depth of brain lesion and impaired consciousness could not be attributed to secondary effects of raised intracranial pressure or to the size of intracranial lesion(s).

A lateral line analogue in cephalopods: water waves generate microphonic potentials in the epidermal head lines of Sepia and Lolliguncula.

Abstract: Many cephalopods have lines of ciliated cells on their head and arms. In the cuttlefishSepia and the squidLolliguncula, electrophysiological recordings clearly identify these epidermal lines as an invertebrate analogue to the mechanoreceptive lateral lines of fish and aquatic amphibians and thus as another example of convergent evolution between a sophisticated cephalopod and vertebrate sensory system. Stimulation of the epidermal lines with local water displacements, generated by a vibrating sphere, causes receptor potentials that have many features known from lateral line microphonic potentials. The minimal threshold of the head lines is 0.2 μm peak-to-peak water displacement (calculated at the skin surface) at 75–100 Hz.

Treatment of Diabetic Foot Infections: Wagner Classification, Therapy, and Outcome

Abstract: A total of 850 cases of septic diabetic foot infections were reviewed in 355 patients. Age, sex, other chronic diseases, site, etiology, Wagner grade, treatment, and results were analyzed. One third of the patients were in their sixth decade of life. There were 180 women and 175 men. Chronic diseases included hypertension, congestive heart disease, and renal failure. Staphylococcus aureus was the most common bacteria. Treatment was considered to meet protocol standards if Wagner's algorithms and infectious disease principles were followed. Thirty-nine Wagner grade 0 infections were seen: only one was not treated appropriately. Eighty-eight percent treated per protocol healed and the one not treated appropriately failed. In grade 1, 79% of the 154 evaluable patients were treated appropriately with a 86% success rate versus a 53% success rate for those not treated per protocol. Of three quarters of the 64 patients with grade 2 infections treated according to protocol, 73% healed. One of those in grade 2 who was not treated according to protocol healed. In grade 3, 64% of the 251 patients were treated per protocol with a 79% success rate versus a 12% success rate for those who were not treated per protocol. Most of the 189 patients with grade 4 cases were treated according to protocol with 88% success; the 20 not treated per protocol had a 15% success rate. Thirty of the 32 grade 5 patients were treated per protocol and all but one healed. Protocol therapy had a statistically significant effect by chi 2 test in the treatment of all groups.