Search PubMed⌕ Search

Biomedical subjects

J W Little

Publications and source records attributed to J W Little.

At least 91 records · Page 5Linked to original sources

Motor recovery in the absence of segmental afferents: a case study of incomplete spinal cord injury.

A 41-year-old male with a prior left L-5/S-1 radiculopathy developed complete quadriplegia following a gunshot wound to the left anterior neck. He subsequently recovered pinprick sensation over the left side of the trunk and lower extremity; and a right peroneal SEP, suggested sparing of long tracts on the right side. Voluntary motor strength gradually recovered more on the left than right for the L-5/S-1 segments, where tendon reflexes were absent. This unique case is discussed with respect to the effect of absent segmental afferents on suprasegmental recovery.

Adult↗

Lower extremity manifestations of spasticity in chronic spinal cord injury.

The prevalence of various manifestations of spasticity from questionnaire responses and from clinical examination of chronic spinal cord injured patients is reported. Extensor spasms, flexor withdrawal spasms, and clonus were reported by most subjects. Those with incomplete lesions reported more interference with activities, more pain, and less functional usefulness, than did those with complete lesions. Extensor spasms were reported to interfere more with transfers, whereas flexor withdrawal spasms were reported to be more frequent at night and to interfere more with sleep. Increased muscle tone was observed more often in extensor than in flexor muscles. Those with incomplete lesions had more hypertonus and more limited passive joint movements than did those with complete lesions. Flexor withdrawal reactions and extensor spasms were also more pronounced in those with incomplete lesions, particularly those with Frankel grade C lesions.

Adult↗

Intradermal tattoo as an adjunct to nipple-areola reconstruction.

Improving results in breast reconstruction have encouraged more authentic restoration of the lost nipple-areola. While recreation of nipple shape can be reliably achieved, appropriate color has remained elusive, except when a composite nipple graft has been harvested from the normal breast, often at a significant aesthetic, emotional, and oncologic cost. Extensive experience with intradermal tattooing of the nipple-areola in over 100 patients over a 5-year period has shown this technique to be exceptionally safe and effective. Both medical-grade and commercial machines are available at varying prices, and medical-grade pigments may be obtained in a variety of authentic flesh tones derived from titanium or iron oxides. In nearly every case, tattooing has helped with either nipple-areola color, size, shape, or position, without any significant complications. Some degree of tattoo fading is common, requiring occasional late touch-ups and, more rarely, complete retattooing.

Aged↗

Implications of the changing medical profile of a dental school patient population.

Representative adult patient populations seeking treatment at a dental school in 1976 and 1986 were analyzed for the prevalence and the characteristics of medical conditions. Patients' records (N = 3,000) were randomly selected from the examination clinics and reviewed for the presence and types of compromising medical conditions. The results indicated a significant increase in the percentage of dental patients who had medical conditions in 1986 as compared with 1976 (P less than .001), as well as significant changes in the types of medical conditions present. These data indicate an increase in the number of patients with medical problems in the general dental school patient population.

Adult↗

Infection control practices of Minnesota dentists: changes during 1 year.

In 1986, a survey of all licensed Minnesota dentists (N = 2,752) was conducted to determine current infection control practices. In 1987, the survey was repeated with a 45% random sample of all Minnesota dentists (N = 1,357) to monitor changes in such practices during 1 year. The findings indicate that dentists made dramatic changes in their routine use of barrier techniques and also, that rates of vaccination against hepatitis B increased decidedly. Younger dentists had higher vaccination rates and use of routine barrier techniques. Although dentists' reluctance to treat patients with AIDS decreased in frequency, some dentists still refuse to treat these patients. However, a substantial majority will treat patients with other infectious diseases.

Adult↗

The medial periareolar approach to submuscular augmentation mammaplasty under local anesthesia.

The medial approach to submuscular augmentation mammaplasty under local anesthesia begins with a medial periareolar incision around one-half or more of the areola. A subcutaneous tunnel is made toward the medial breast border, avoiding mammary ducts and sensory nerves to the nipple. The breast is reflected laterally, exposing a patch of pectoralis major muscle. A submuscular pocket is then created beneath portions of the pectoralis major, rectus abdominis, external oblique abdominis, and serratus anterior muscles, after which the implant is inserted and the muscle, dermis, and skin are closed sequentially. The periareolar incision allows for favorable scars without compromising the access or exposure necessary for accurate implant placement. Complete muscle coverage of the implant should contribute to a lower rate of capsular contracture. With a medial submuscular approach, nipple sensation is rarely altered, and revisions, if necessary, can be done through the same incision, still under local anesthesia, for increased safety, economy, and convenience. The medial approach to breast augmentation is a highly versatile, safe, and consistent method of achieving excellent results in breast augmentation in terms of scar, symmetry, and softness.

Adult↗

Locomotor recovery following subtotal spinal cord lesions in a rat model.

Locomotor function is described over 4 weeks in adult rats recovering from mid-thoracic spinal cord lesions, sparing the left lateral and/or ventral funiculus. A composite locomotor score was developed to follow changes by grading the swing and stance phases of locomotion, hindleg struggling withdrawal, and hopping. Motor recovery was more rapid in left than right hindlegs, consistent with sparing of left supraspinal pathways. Two temporal phases of recovery were noted in some animals, perhaps arising from two different recovery mechanisms. Motor recovery in the right hindleg was similar whether a left lateral or ventral funiculus was spared.

Animals↗

Electrodiagnosis and recovery of function.

The study of electrodiagnosis with respect to recovery of function is in its infancy. There is a need for better understanding of the mechanisms of recovery and for better techniques to monitor recovery. This paper reviews the potential uses and limitations of current electrodiagnostic tests to predict and monitor neuromuscular recovery. It illustrates the use of these techniques in patients with spinal cord injury.

Adult↗

Isolation and characterization of noncleavable (Ind-) mutants of the LexA repressor of Escherichia coli K-12.

The LexA repressor of Escherichia coli represses a set of genes that are expressed in the response to DNA damage. After inducing treatments, the repressor is inactivated in vivo by a specific cleavage reaction which requires an activated form of RecA protein. In vitro, specific cleavage requires activated RecA at neutral pH and proceeds spontaneously at alkaline pH. We have isolated and characterized a set of lexA mutants that are deficient in in vivo RecA-mediated cleavage but retain significant repressor function. Forty-six independent mutants, generated by hydroxylamine and formic acid mutagenesis, were isolated by a screen involving the use of operon fusions. DNA sequence analysis identified 20 different mutations. In a recA mutant, all but four of the mutant proteins functioned as repressor as well as wild-type LexA. In a strain carrying a constitutively active recA allele, recA730, all the mutant proteins repressed a sulA::lacZ fusion more efficiently than the wild-type repressor, presumably because they were cleaved poorly or not at all by the activated RecA protein. These 20 mutations resulted in amino acid substitutions in 12 positions, most of which are conserved between LexA and four other cleavable proteins. All the mutations were located in the hinge region or C-terminal domain of the protein, portions of LexA previously implicated in the specific cleavage reactions. Furthermore, these mutations were clustered in three regions, around the cleavage site (Ala-84-Gly-85) and in blocks of conserved amino acids around two residues, Ser-119 and Lys-156, which are believed essential for the cleavage reactions. These three regions of the protein thus appear to play important roles in the cleavage reaction.

Amino Acid Sequence↗

Reinnervation of the trapezius muscle.

The eleventh cranial nerve shoulder syndrome, which results from denervation of the trapezius muscle, contributes significantly to the postoperative morbidity of radical neck dissections. Multiple techniques exist for the reinnervation of muscles that have injured motor nerves. Reinnervation of denervated trapezius muscles was examined in the New Zealand white rabbit by use of three techniques of reinnervation: (1) neuromuscular pedicle transfer of the accessory nerve from the trapezius muscle, (2) direct accessory nerve implantation, and (3) neuromuscular pedicle transfer of the accessory nerve from the sternocleidomastoid muscle. The reinnervated trapezius muscles were examined grossly by direct nerve stimulation, electrophysiologically by evoked electromyography, and histologically by enzymatic muscle staining and silver-reducing nerve staining. The gross, electrophysiologic, and histologic results confirmed successful reinnervation of the trapezius muscle within 6 weeks of operation. No significant difference was observed between the various techniques of reinnervation.

Accessory Nerve↗

The temporal fossa in head and neck reconstruction: twenty-two flaps of scalp, fascia, and full-thickness cranial bone.

We reviewed 22 consecutive flaps based on the blood supply of the temporal fossa. Our purpose was to demonstrate reliability of the vascular supply and to illustrate the versatility of these tissues for reconstruction of specialized structures, including eyelids, eyebrow, ear, lips, oral lining, orbit, and mandible. For these complex problems, all but one patient required multiple-stage surgery to obtain their final aesthetic and functional results. All flaps proved reliable and versatile. Their advantages include proximity to the reconstructive site, ease of bilateral reconstructions, and well-camouflaged donor deficit. In particular, the ability to transfer vascularized full-thickness cranial bone for total or bilateral mandibular reconstructions presents an additional possibility for this difficult problem. We conclude that the reconstructive potential of these flaps is limited only by the surgeon's ingenuity.

Craniocerebral Trauma↗

Lysine-156 and serine-119 are required for LexA repressor cleavage: a possible mechanism.

LexA repressor of Escherichia coli is inactivated in vivo by a specific cleavage reaction requiring activated RecA protein. In vitro, cleavage requires activated RecA at neutral pH and proceeds spontaneously at alkaline pH. These two cleavage reactions have similar specificities, suggesting that RecA acts indirectly to stimulate self-cleavage, rather than directly as a protease. We have studied the chemical mechanism of cleavage by using site-directed mutagenesis to change selected amino acid residues in LexA, chosen on the basis of kinetic data, homology to other cleavable repressors, and potential similarity of the mechanism to that of proteases. Serine-119 and lysine-156 were changed to alanine, a residue with an unreactive side chain, resulting in two mutant proteins that had normal repressor function and apparently normal structure, but were completely deficient in both types of cleavage reaction. Serine-119 was also changed to cysteine, another residue with a nucleophilic side chain, resulting in a protein that was cleaved at a significant rate. These and other observations suggest that hydrolysis of the scissile peptide bond proceeds by a mechanism similar to that of serine proteases, with serine-119 being a nucleophile and lysine-156 being an activator. Possible roles for RecA are discussed.

Amino Acid Sequence↗

The psychological contribution of nipple addition in breast reconstruction.

Two groups of consecutive patients from two different plastic surgical practice populations were evaluated to determine psychosocial differences between those who underwent nipple-areola reconstruction in addition to breast reconstruction (N = 33) versus those who did not undergo nipple-areola reconstruction in addition to breast reconstruction (N = 26). Psychological assessment consisted of a standardized symptom inventory (Brief Symptom Inventory) and a specially designed self-report questionnaire investigating reactions unique to surgeries for breast cancer and breast reconstruction. Both groups were equivalent sociodemographically, with the exception of age, where the nipple-added group was significantly younger (P = 0.035) than the nipple-not-added group. The nipple-added group reported significantly greater satisfaction with breast reconstruction with regard to overall satisfaction (P = 0.004), satisfaction with size (P = 0.02), satisfaction with softness (P = 0.0004), sexual sensitivity (P = 0.006), and satisfaction with nude appearance (P = 0.02). Of the nine scales of clinical symptomatology on the Brief Symptom Inventory, the nipple-added group showed more increased symptoms on seven of the nine. The nipple-added group was significantly higher on two of these scales, namely, paranoid ideation (P = 0.009) and anxiety (P = 0.03).

Adult↗

Compliance with guidelines for management of dental school patients susceptible to infective endocarditis.

The purpose of the investigation was to determine the extent to which the 1984 American Heart Association prophylaxis guidelines were adopted in a sample of dental school patients and to determine whether implementation strategies resulted in change in the management of patients at risk for infective endocarditis (IE). Dental records of 330 patients requiring medical consultation on the basis of a heart problem identified in the medical history questionnaire were reviewed. One hundred fifty-four patients required IE prophylaxis according to their physicians. Only 11 percent of IE-susceptible patient charts showed documentation of correct prophylaxis for every appointment at which a bacteremia was possible. Only 35 percent of patients receiving prophylaxis after December 1984 were covered according to the new American Heart Association guidelines.

Anti-Bacterial Agents↗

Neurogenic heterotopic ossification.

Neurogenic heterotopic ossification is a potential sequela of neurological disorders, especially spinal cord injury and head injury. The etiology is unknown. Clinical, radiologic, and bone scan findings are typical. Complications may threaten function. The differential diagnosis is crucial in its early stages. Treatment options include diphosphonates, non-steroidal anti-inflammatory drugs, and surgery. This article has reviewed the literature on neurogenic heterotopic ossification (HO), soft tissue ossification of neurologic disease, including pathogenesis, histology, presentation, diagnosis, natural history, complications, and current treatments.

Animals↗