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Biomedical subjects

B Lester

Publications and source records attributed to B Lester.

At least 19 recordsLinked to original sources

Neurobehavioral effects of treatment for opiate withdrawal.

A partially randomised, controlled trial was performed to test the hypothesis that opiate exposed infants treated with diluted tincture of opium (DTO) and phenobarbital would have better neurobehavioral scores than infants treated with DTO alone. Compared with those treated with DTO alone (n = 15), infants treated with DTO and phenobarbital (n = 17) were more interactive, had smoother movements, were easier to handle, and less stressed. Dual treatment results in improved neurobehavioral organisation during the first three weeks of life, which may indicate a more rapid recovery from opiate withdrawal.

Analgesics, Opioid↗

Infant colic and feeding difficulties.

AIMS: To examine the relation between colic and feeding difficulties and their impact on parental functioning for a primarily clinic referred sample. METHODS: Forty three infants (and their mothers) were enrolled between 6 and 8 weeks of age. Infants were divided into two groups, colic (n = 19) and comparison (n = 24), based on a modified Wessel rule of three criteria for colic. Families were assessed at two visits; one occurred in the laboratory and one occurred in a paediatric radiology office. Outcome measures included the clinical assessment of infant oral motor skills, behavioural observation of mother-infant feeding interactions, maternal questionnaires on infant crying, sleeping and feeding behaviours, and the occurrence of gastro-oesophageal reflux (GOR) in the infants using abdominal ultrasound. RESULTS: Infants in the colic group displayed more difficulties with feeding; including disorganised feeding behaviours, less rhythmic nutritive and non-nutritive sucking, more discomfort following feedings, and lower responsiveness during feeding interactions. Infants in the colic group also had more evidence of GOR based on the number of reflux episodes on abdominal ultrasound as well as maternal report of reflux. Mothers in the colic group reported higher levels of parenting stress. CONCLUSIONS: Results provide the first systematic evidence of feeding problems in a subgroup of infants with colic. Data also illustrate the impact of these difficulties on parental and infant functioning. The association between feeding difficulties and colic suggests the potential for ongoing regulatory problems in infants presenting with clinically significant colic symptoms.

Adult↗

Central and autonomic system signs with in utero drug exposure.

AIMS: To determine risk for central nervous system/autonomic nervous system (CNS/ANS) signs following in utero cocaine and opiate exposure. METHODS: A multisite study was designed to determine outcomes of in utero cocaine and opiate exposure. A total of 11 811 maternal/infant dyads were enrolled. Drug exposed (EXP) infants were identified by maternal self report of cocaine or opiate use or by meconium testing. Of 1185 EXP, meconium analysis confirmed exposure in 717 to cocaine (CO) only, 100 to opiates (OP), and 92 to opiates plus cocaine (OP+CO); 276 had insufficient or no meconium to confirm maternal self report. Negative exposure history was confirmed in 7442 by meconium analysis and unconfirmed in 3184. Examiners masked to exposure status, assessed each enrolled infant. Using generalised estimating equations, adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated for manifesting a constellation of CNS/ANS outcomes and for each sign associated with cocaine and opiate exposure. RESULTS: Prevalence of CNS/ANS signs was low in CO, and highest in OP+CO. Signs were significantly related to one another. After controlling for confounders, CO was associated with increased risk of manifesting a constellation of CNS/ANS outcomes, OR (95% CI): 1.7 (1.2 to 2.2), independent of OP effect, OR (95% CI): 2.8 (2.1 to 3.7). OP+CO had additive effects, OR (95% CI): 4.8 (2.9 to 7.9). Smoking also increased the risk for the constellation of CNS/ANS signs, OR (95% CI) of 1.3 (1.04 to 1.55) and 1.4 (1.2 to 1.6), respectively, for use of less than half a pack per day and half a pack per day or more. CONCLUSION: Cocaine or opiate exposure increases the risk for manifesting a constellation of CNS/ANS outcomes.

Adult↗

Isolated fracture of the trapezoid.

We describe a case of an isolated trapezoid fracture that was managed nonoperatively with a favorable clinical outcome. To our knowledge and based on a literature review, this is the first report of a true isolated trapezoid fracture without accompanying dislocation and without associated metacarpal, carpal, or distal radial fractures. We present our findings in this case and review the clinical presentation, diagnostic workup, and treatment of trapezoid fractures in general.

Adult↗

Mycobacterium tuberculosis infection of the wrist.

Reports of tuberculous infections of the wrist have been scarce, especially during the past 30 years. The diagnosis of tuberculosis may be difficult and requires a high index of suspicion, especially in patients with significant risk factors. Prompt diagnosis and treatment are crucial, as untreated wrist infections can have disastrous outcomes. This article describes the clinical presentation and management of an atypical case of tuberculosis of the wrist--a case of extensive carpal destruction without tenosynovial involvement. Quiescent tuberculosis seemed to reactivate after an episode of minor trauma.

Adult↗

AGS3 inhibits GDP dissociation from galpha subunits of the Gi family and rhodopsin-dependent activation of transducin.

A number of recently discovered proteins that interact with the alpha subunits of G(i)-like G proteins contain homologous repeated sequences named G protein regulatory (GPR) motifs. Activator of G protein signaling 3 (AGS3), identified as an activator of the yeast pheromone pathway in the absence of the pheromone receptor, has a domain with four such repeats. To elucidate the potential mechanisms of regulation of G protein signaling by proteins containing GPR motifs, we examined the effects of the AGS3 GPR domain on the kinetics of guanine nucleotide exchange and GTP hydrolysis by G(i)alpha(1) and transducin-alpha (G(t)alpha). The AGS3 GPR domain markedly inhibited the rates of spontaneous guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) binding to G(i)alpha and rhodopsin-stimulated GTPgammaS binding to G(t)alpha. The full-length AGS3 GPR domain, AGS3-(463-650), was approximately 30-fold more potent than AGS3-(572-629), containing two AGS3 GPR motifs. The IC(50) values for the AGS3-(463-650) inhibitory effects on G(i)alpha and transducin were 0.12 and 0.15 microm, respectively. Furthermore, AGS3-(463-650) and AGS3-(572-629) effectively blocked the GDP release from G(i)alpha and rhodopsin-induced dissociation of GDP from G(t)alpha. The potencies of AGS3-(572-629) and AGS3-(463-650) to suppress the GDP dissociation rates correlated with their ability to inhibit the rates of GTPgammaS binding. Consistent with the inhibition of nucleotide exchange, the AGS3 GPR domain slowed the rate of steady-state GTP hydrolysis by G(i)alpha. The catalytic rate of G(t)alpha GTP hydrolysis, measured under single turnover conditions, remained unchanged with the addition of AGS3-(463-650). Altogether, our results suggest that proteins containing GPR motifs, in addition to their potential role as G protein-coupled receptor-independent activators of Gbetagamma signaling pathways, act as GDP dissociation inhibitors and negatively regulate the activation of a G protein by a G protein-coupled receptor.

Amino Acid Motifs↗

The wire interlock technique for harvesting a partial-width distally attached tendon graft.

A wire interlock technique useful for harvesting a partial-width tendon graft with an intact insertion for local reconstructive procedures is described. This technique is rapid and reliable for procuring attached tendon grafts with minimal exposure. The technique was used to harvest a flexor carpi radialis tendon graft for basal joint interposition arthroplasty in 12 patients. This method also may be readily applicable for other procedures requiring local ligament reconstruction with a partial-width tendon graft. (J Hand Surg 2000; 25A:176-182.

Bone Wires↗

A simple effective splinting technique for the mallet finger.

We describe an inexpensive, simple, and effective technique for the closed treatment of mallet fingers. This technique splints the mallet finger in 0 degrees of extension. It is simple, readily reproducible, and easy to use, requiring materials that are readily available to any physician. Thirty-seven patients, ages 21 to 65 years, presented with a closed mallet finger injury at day zero to 5 months after injury. Ten of these patients had a fracture. All were treated with this splinting technique. We report excellent results in 35 of 37 patients, who recovered either complete or near-complete active extension. Our results compare favorably with results from other techniques and splints.

Adult↗

Circadian coordination of cancer growth and metastatic spread.

To understand whether mammalian circadian time structure measurably affects the host-cancer balance, we studied tumor-take frequency after s.c. tumor cell inoculation and the number of pulmonary tumor nodules after i.v. tumor cell injections at each of 6 equispaced times of day. We employed 2 genetically distinct mouse strains and 2 different tumor model systems, a methylcholanthrene A-induced fibrosarcoma of C(3)HeJ mice and 2 B(16) melanoma cell lines of vastly different metastatic efficiency in C57 Black/6 mice. Fibrosarcoma cells were injected s.c. in 1 of 8 different doses, at 1 of 8 permutated anatomic sites and at 1 of 6 equispaced circadian times, in 96 female C(3)HeJ mice maintained under a synchronizing schedule of 12 hr light alternating with 12 hr dark. Regardless of tumor cell dose and inoculum location, tumor-take frequency depended strongly upon the circadian stage of tumor cell inoculation. Injections of between 2,000 and 50,000 live tumor cells inoculated near the daily sleep/wake interface resulted in the lowest incidence of tumor take compared with inoculation at other times of day. In the experimental i.v. B(16) melanoma metastatic model (N = 110), the capacity of both high and low metastatic potential clones to successfully metastasize to lung depended, to a large extent, upon when in the day each of these clones was injected. Similar to the fibrosarcoma data, the daily sleep/wake boundary was the time of day associated with the greatest resistance to metastatic spread.

Animals↗

Quadrilateral space syndrome: diagnosis, pathology, and treatment.

Quadrilateral space syndrome is an infrequent, recently established neurovascular compression syndrome affecting young active adults. With this syndrome, the neurovascular bundle, consisting of the posterior humeral circumflex artery (PHCA) and the axillary nerve, is compressed by fibrotic bands as it traverses the quadrilateral space. Symptoms result from compression of the axillary nerve, not from PHCA occlusion. Because of the vague, often nonspecific, clinical presentation of patients with quadrilateral space syndrome, diagnosis is challenging and requires a high index of suspicion from the orthopedist. Subclavian arteriography confirms the diagnosis. Treatment is usually conservative; operative management is reserved for selected patients. A posterior approach with detachment of the deltoid and teres minor muscles is recommended for surgical decompression and for lysis of fibrous tissue. We report two cases of persistent quadrilateral space syndrome in young adults, treated surgically, with 2-year follow-up. In the present report, diagnostic criteria, pathology, management, operative technique, and recent literature are also reviewed.

Adult↗

Central and autonomic nervous systems' signs associated with in utero exposure to cocaine/opiates.

In summary, we found that the prevalence of CNS/ANS signs was significantly higher in the infants exposed to cocaine and/or opiates than in nonexposed infants. However, the prevalence of a large number of these signs was less than 5%. The prevalence rates of these signs are lower when exposure involved cocaine only; thus, their assessment has limited clinical utility.

Autonomic Nervous System Diseases↗

The vulnerable preschool child: the impact of biomedical and social risks on neurodevelopmental function.

The scope of preschool children with biological risk and social disadvantage is large and includes over 1 million (28%) newborns per year. Currently in 1996, 7% of children are born with low birth weight, 1% are born with very low birth weight, 20% have alcohol exposure, and 10% have other drug exposure. Poverty is dynamic and impacts on 25% of children less than 6 years old with increased frequency in children who are minority, have mothers with less than a high school education, or are unmarried. There has been a markedly increased survival in very low birth weight and extremely low birth weight infants in the past 10 years. Outcomes of these neonatal populations reveals that parenchymal brain injury is the major predictor of cerebral palsy which occurs in 7% to 10% of very low birth weight survivors. However, poverty is the major predictor of low IQ. Fetal alcohol syndrome occurs in 1.9 per 1,000 births and is most often associated with mild mental retardation and educational underachievement. Studies investigating cocaine revealed that it is a multifactorial problem overlapping with polysubstance abuse and other risk factors for social disadvantage. The overwhelming number of children do not have cerebral palsy or severe mental retardation. The long-term impact is more subtle and needs more systematic analysis as well as critical evaluation of cognitive impairments and educational under-achievement. Hypoxic ischemic encephalopathy (HIE) cannot be determined by one biological measure. Though multiple disability occurs in 70% of children with Sarnat stage 3 HIE, 30% of survivors are not disabled. Children with mild to moderate HIE have long-term outcomes that are influenced by 9- to 12-month neurodevelopmental status and social disadvantage. By combining strategies to lessen biological risks and enhance developmentally appropriate environments, long-term outcomes of preschool children can be optimized.

Asphyxia Neonatorum↗

Impending malunions of the hand. Treatment of subacute, malaligned fractures.

Malunions of the hand present a challenging problem to the orthopaedic surgeon. Angular and rotational deformities, and shortening and articular incongruity, can lead to significant functional impairment or dysesthetic appearance. The prevention of malunion should remain a primary goal. When displaced fractures of the metacarpals or phalanges present within the first or second weeks, properly performed closed or open reduction with percutaneous pinning or internal fixation are excellent options with predictable results. Malaligned fractures that present later frequently cannot be readily reduced. Once fully united, treatment options have included corrective osteotomy if function is significantly impaired or if appearance is objectionable; for patients who are not suitable for surgery for medical or other reasons, or for whom appearance is acceptable, intensive occupational therapy to maximize function may yield sufficiently serviceable clinical results. During the past several years, the senior author (BL) has chosen to be more proactive in the prevention of malunions of the hand. In the authors' experience, results of aggressive surgical treatment of subacute, malaligned fractures in selected patients have produced results comparable with or superior to those reported for later reconstructive procedures. With the proliferation of managed care, there has been an increasing frequency of delayed referral patterns for fracture treatment by hand specialists. Definitive treatment of these "impending malunions" is preferable to passive treatment delay and secondary reconstructive procedures, offering both earlier correction of alignment and earlier opportunity for return of function.

Adolescent↗

MRI of the Stener lesion.

OBJECTIVE: To assess the utility of MR in detecting surgically induced Stener lesions (displaced thumb ulnar collateral ligaments) in cadaveric models. DESIGN: Six cadaver thumbs had ulnar collateral ligament (UCL) tears created surgically. MR examinations (2D STIR and 3D GRASS) were performed identically on all specimens both before displacement (non-Stener) and after displacement (Stener lesion) of the UCL. The MR images were then randomly numbered. Each image was evaluated separately in blinded fashion by four musculoskeletal radiologists for the presence or absence of a Stener lesion. Each radiologist reinterpreted the images after an interval of several days. The interpretation was based on previously published criteria for Stener lesion diagnosis by MR. RESULTS: The sensitivity of GRASS ranged from 0.17 to 0.67 with the most experienced reader scoring the lowest. The specificity of GRASS ranged from 0.33 to 1.0 (most experienced reader 0.67, 0.83). STIR had a sensitivity of 0.00-0.17 and a specificity of 0.53-0.83. The kappa values for inter- and intraobserver agreement were measured. The intraobserver kappa for GRASS was 0.27-0.75 (most experienced reader 0.75). CONCLUSIONS: 2D imaging is probably inadequate for the evaluation of Stener lesions. The most likely reason is that the STIR slice thickness of 3 mm limits resolution of small UCLs. The poor sensitivity and specificity of GRASS as well as poor interobserver agreement suggest that MR may not be sufficiently accurate for Stener lesion evaluation.

Humans↗

"Press test" for office diagnosis of triangular fibrocartilage complex tears of the wrist.

We present a simple provocative diagnostic office test for detection of triangular fibrocartilage complex tears of the wrist. Twenty-seven patients with a working diagnosis of a triangular fibrocartilage complex tear complained of wrist pain caused by forceful use; 18 had a history of trauma. A "press test" was performed in each, requiring the seated patient to push the body weight up off a chair using the affected wrist, creating an axial ulnar load. A positive test provoked focal ulnar wrist pain replicating the discomfort that had prompted the patient to seek medical attention. Thirteen patients improved with conservative treatment. Seventeen underwent magnetic resonance imaging (showing 13 tears and 4 normal results) and two patients had arthrograms (both had tears). Fourteen patients had wrist arthroscopy; all had triangular fibrocartilage complex tears, which were debrided, with postoperative clinical improvement. As verified by arthroscopy, the press test had 100% sensitivity in preoperative tear detection compared with 79% for magnetic resonance imaging. The press test is recommended as a useful, free, noninvasive clinical test for triangular fibrocartilage complex tears of the wrist.

Adult↗