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Biomedical subjects

M S Williams

Publications and source records attributed to M S Williams.

At least 37 records · Page 2Linked to original sources
PubMed1997

Unusual autosomal recessive lymphatic anomalies in two unrelated Amish families.

We report on two unrelated Amish families with familial occurrence of unusual lymphatic anomalies. The first family had two children, a boy and a girl, with congenital chylothorax both of whom died as a consequence of this condition (one prenatally and one neonatally). The second family has two brothers with isolated cystic hygroma. Neither family has any other individuals affected with any type of lymphatic anomaly. Differential diagnosis and presumed autosomal recessive inheritance pattern will be discussed. Familial cystic hygroma not associated with hydrops fetalis and neonatal death has not been reported previously.

Chylothorax↗
PubMed1997

Autosomal dominant hypohidrotic ectodermal dysplasia in a large family.

We have studied an autosomal dominant hypohidrotic ectodermal dysplasia in 38 individuals over six generations in one family. Thirty-two affected individuals in four generations are still living. Questionnaire responses were received from 21 of the affected relatives and some of the individuals were examined by one of the authors. Smooth, dry, thin skin is seen in most affected individuals. Nearly all have fine, slow-growing scalp and body hair and all have sparse eyebrows and short eyelashes. Nearly all show a decrease in sweating, with some only sweating under the arms and/or on the palms and soles. All affected individuals lacked some deciduous teeth and some permanent teeth. Some teeth are abnormally shaped. Nail abnormalities are more variable and may occur more frequently with increasing age. No other abnormalities are seen in affected individuals in this family. We reviewed 40 autosomal dominant ectodermal dysplasia syndromes. This family bears some resemblance to a family described by Jorgensen et al. [1987]; however, it appears to represent a disorder that has not been described previously.

Abnormalities, Multiple↗
PubMed1997

Spinal deformity in myelodysplasia. Correction with posterior pedicle screw instrumentation.

STUDY DESIGN: A retrospective review of transpedicular instrumentation used in a series of 24 patients with myelodysplastic spinal deformities and deficient posterior elements. OBJECTIVE: To describe the usefulness and efficacy of these instruments in the treatment of complicated myelodysplastic spinal deformity. METHODS: The mean preoperative scoliosis was 75.7 degrees (range, 39-130 degrees) in the 22 patients with scoliotic deformities; 4 patients with thoracic hyperkyphoses averaged 70.5 degrees (range, 46-90 degrees) and 10 patients with lumbar kyphoses averaged 80.5 degrees (range, 42-120 degrees). The instrumentation extended to the sacrum in 4 patients and the pelvis in 9; 10 patients also underwent anterior release and fusion and 7 underwent concomitant spinal cord detethering. At an average follow-up of 4.0 years (2.0-7.7 years; one patient died at 8 months), all patients have fused (with the exception of two lumbosacral pseudarthroses). RESULTS: At last follow-up, deformity measured 32.1 degrees scoliosis (range, 6-85 degrees), 30.8 degrees thoracic kyphosis (range, 24-35 degrees), and 0.0 degree lumbar kyphosis (range, 35 degrees kyphosis to 29 degrees lordosis). Three patients lost some neurologic function after surgery; two recovered within 6 months and one has incomplete recovery. No ambulatory patient lost the ability to walk. Five patients required additional surgical procedures; in three cases, there was instrumentation breakage associated with pseudarthrosis or unfused spinal segments. CONCLUSIONS: Pedicle screw instrumentation is uniquely suited to the deficient myelodysplastic spine. Compared with historical control subjects, these devices have proven capable of significant correction of both scoliotic and kyphotic deformities. This instrumentation appears particularly useful in preserving lumbar lordosis in all patients and may preserve more lumbar motion in ambulatory myelodysplasia patients.

Adolescent↗
PubMed1997

Smith-Lemli-Opitz syndrome: thirty-year follow-up of "S" of "RSH" syndrome.

We have reassessed patient "S," one of the first 3 individuals recognized to have Smith-Lemli-Opitz (or RSH) syndrome, at age 34 years, and we describe his physical, developmental, and behavioral manifestations. This reassessment provides formal evidence that this individual has the cholesterol biosynthetic defect which is thought to be the cause of Smith-Lemli-Opitz syndrome. Dietary manipulation appears to have had a beneficial effect on the patient's behavior and suggests that even in adults with this condition, dietary cholesterol supplementation may be indicated.

Adult↗
PubMed1997

Do CTL kill target cells by inducing apoptosis?

Inhibitors of ICE-family proteases (caspases) block many examples of apoptotic cell death in vivo and in vitro, including multiple apoptotic stimuli for T lymphocytes. We have tested whether cell death induced by cytotoxic T lymphocytes was also blocked by caspase inhibitors. We found that the rapid apoptotic target cell death induced by Fas ligand-bearing CTL using the target Fas death pathway was efficiently blocked by caspase inhibitors. In contrast, target lysis induced by the CTL granule exocytosis pathway is not detectably blocked by such inhibitors, although the accompanying apoptotic nuclear damage is efficiently blocked. Thus caspase inhibitors prevent the hallmark phenotype of apoptosis without measurably affecting target cell death as evidenced by lysis.

Animals↗
PubMed1997

Target cell lysis by CTL granule exocytosis is independent of ICE/Ced-3 family proteases.

Activation of ICE/Ced-3 family proteases (caspases) has been proposed to mediate both the granule exocytosis and Fas-Fas ligand pathways of rapid target cell death by cytotoxic T lymphocytes. In agreement with this model, two peptide fluoromethyl ketone caspase inhibitors and baculovirus p35 blocked apoptotic nuclear damage and target cell lysis by the CTL-mediated Fas-Fas ligand pathway. The peptide caspase inhibitors also blocked drug-induced apoptotic cell death in tumor cells. In contrast, the caspase inhibitors blocked CTL granule exocytosis-induced target apoptotic nuclear damage, but did not inhibit target lysis. These results are consistent with recent demonstrations that granzyme B can activate caspases leading to apoptotic nuclear damage, but show that target cell lysis by CTL granule exocytosis occurs by a caspase-independent pathway.

Animals↗
PubMed1997

A new technique for removal of intraarticular bullet fragments from the femoral head.

Removal of foreign bodies from a joint usually involves an extensive surgical approach. The necessity for intraarticular bullet removal has been well documented in the literature. The conventional approach for bullet extraction usually requires an open arthrotomy, arthroscopic removal or, in most cases, a combination of the two. This report involves a previously undocumented technique for bullet removal from the hip. A Synthes DHS Triple Reamer was inserted through a limited lateral incision over a guide pin that had been placed under fluoroscopic guidance. The tip of the guide pin was positioned in contact against the bullet fragments in both the anteroposterior and lateral planes. The fragments were then removed through the reamed canal. This technique allows for bullet removal without the inherent risks associated with an open arthrotomy and without the special skills required for hip arthroscopy. It is relatively easy to perform and may prove to be a valuable tool in the arsenal of orthopedists who deal with specific gunshot wounds to the hip region.

Adult↗
PubMed1996

Role of reactive oxygen intermediates in TCR-induced death of T cell blasts and hybridomas.

The functional role of reactive oxygen intermediates (ROI) in activation-induced death of mature T lymphocytes and hybridomas was tested using antioxidants and inhibitors of enzymes that generate oxidants. These agents were shown to inhibit TCR-triggered death in a concentration-dependent manner, suggesting a possible role of ROI in this death. Since the TCR-induced death of both human T blasts and the murine T cell hybridoma 2B4 involve an initial step of TCR-induced Fas ligand (FasL) up-regulation followed by a lethal step induced by Fas cross-linking, both steps were examined separately for ROI dependence. The thiol antioxidants N-acetyl cysteine and glutathione blocked Fas-induced death triggered via cross-linking either by IgM anti-Fas or cell-bound FasL, while the other inhibitors of activation-induced death did not block this late lethal step. None of the agents used blocked early events after TCR ligation, as seen by the lack of inhibition of IL-2 secretion or CD69 up-regulation. However, the nonthiol agents that blocked activation-induced death all blocked FasL up-regulation induced by TCR signals in the hybridoma, as measured by a functional assay. Agents inhibiting FasL up-regulation also inhibited activation-induced ROI generation in the hybridoma, as detected by flow cytometry using dihydrorhodamine oxidation. Furthermore, a good correlation was found between the extent of ROI generation and functional FasL expression in 2B4 cells. Thus, while ROI do not appear to act as downstream mediators of apoptotic death induced by steroid or Fas cross-linking in T cells, they are generated by TCR signaling and appear to participate in FasL up-regulation.

Animals↗
PubMed1996

Phase III double-blind evaluation of an aloe vera gel as a prophylactic agent for radiation-induced skin toxicity.

PURPOSE: Considerable pilot data and clinical experience suggested that an aloe vera gel might help to prevent radiation therapy-induced dermatitis. METHODS AND MATERIALS: Two Phase III randomized trials were conducted. The first one was double blinded, utilized a placebo gel, and involved 194 women receiving breast or chest wall irradiation. The second trial randomized 108 such patients to aloe vera gel vs. no treatment. Skin dermatitis was scored weekly during both trials both by patients and by health care providers. RESULTS: Skin dermatitis scores were virtually identical on both treatment arms during both of the trials. The only toxicity from the gel was rare contact dermatitis. CONCLUSIONS: This dose and schedule of an aloe vera gel does not protect against radiation therapy-induced dermatitis.

Adult↗
PubMed1996

Covalent crosslinking of the heme prosthetic group to myoglobin by H2O2: toxicological implications.

It is known that treatment of myoglobin with H2O2 leads to covalent alteration of the heme prosthetic group with concomitant formation of a protein bound heme adduct and transforms myoglobin from an oxygen storage protein to an oxidase. In the current study it was shown, with the use of 14C-labeled heme reconstituted into apomyoglobin, that up to 88% of the oxidatively altered heme can be accounted for by the protein bound product. Furthermore, a partially purified preparation of the protein bound heme adduct was introduced into human fibroblasts using the method of osmotic lysis of pinosomes and found to cause cell death (40%) within 1 h, as evidenced by trypan blue exclusion. Native myoglobin introduced into cells in the same manner or extracellular treatment by the protein bound heme adduct had no effect on cell viability. The extent of cell death could be decreased (50%) by N-acetyl-L-cysteine, indicating a potential role for reactive oxygen intermediates in this process. These results show that the covalently altered myoglobin can elicit cellular damage and suggests that similar processes may occur in vivo in pathologic conditions such as that involving cardiac ischemia and reperfusion injury, where covalently altered myoglobin may form.

Acetylcysteine↗
PubMed1996

Effects of tempered barley on milk yield, intake, and digestion kinetics of lactating Holstein cows.

The effects on milk yield and digestion kinetics were compared when tempered (10% water added 24 h prior to processing and feeding), rolled barley and dry, rolled barley were fed in trial 1, or tempered, whole barley, and dry, rolled barley were fed in trial 2. In trial 1, the diet based on tempered, rolled barley resulted in increased milk yield (5%), efficiency (10%), and apparent digestibility of dietary DM (6%), NDF (15%), ADF (12%), CP (10%), and starch (4%). Mean fractional rate of passage was slower for tempered (7.8%/h) than for dry (8.6%/h) barley particles. Mean fractional rate of passage of forage particles and rates of digestion of forage and concentrate did not differ. The percentage of particle washout from an in situ bag (pore size, 53 mu) was 21% for dry barley and 6% for tempered barley, indicating that tempering reduced the pool size of small particles in rolled barley. In trial 2, the diet based on tempered, whole barley resulted in decreased daily milk yield (5%), efficiency (11%), and apparent digestibility of dietary DM (16%), CP (10%), and starch (8%). The results indicated that tempered, rolled barley can be effectively used in diets for high yielding dairy cows to increase yield and efficiency; however, tempered barley must be rolled to achieve these effects.

Animal Feed↗