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Biomedical subjects

C Zinman

Publications and source records attributed to C Zinman.

At least 19 recordsLinked to original sources
PubMed2000

Unexpected Ebola virus in a tertiary setting: clinical and epidemiologic aspects.

OBJECTIVES: To describe the clinical manifestations of viral hemorrhagic fever, and to increase clinicians' awareness and knowledge of these illnesses. DESIGN: Retrospective study of the clinical and laboratory data and management of two cases of Ebola virus infection with key epidemiologic data provided. SETTING: Two tertiary care hospitals. PATIENTS: Two adult patients, the index case and the source patient, both identified as having Ebola, one of whom originated in Gabon. INTERVENTIONS: One patient was admitted to the intensive care unit. The other was managed in a general ward. MEASUREMENT AND MAIN RESULTS: Clinical and laboratory data are reported. One patient, a healthcare worker who contracted this illness in the course of her work, died of refractory thrombocytopenia and an intracerebral bleed. The source patient survived. Despite a long period during which the diagnosis was obscure, none of the other 300 contacts contracted the illness. CONCLUSIONS: Identification of high-risk patients and use of universal blood and body fluid precautions will considerably decrease the risk of nosocomial spread of viral hemorrhagic fevers.

Adult↗
PubMed1999

Treatment of experimental avascular necrosis of the femoral head with hyperbaric oxygen in rats: histological evaluation of the femoral heads during the early phase of the reparative process.

The healing of vascular deprivation-induced necrosis of the femoral head of rats exposed to hyperbaric oxygen was compared with that in untreated rats. The amount of necrotic bone, extent of osteoneogenesis, degree of remodeling, and changes of the articular cartilage were histologically graded on a semiquantitative scale of 0 to 3+. On the 2nd, 7th, and 21st postoperative days, there were no differences between the two groups. Newly formed appositional and intramembranous bone was more abundant and remodeling was more advanced in the femoral heads of the hyperbaric oxygen-treated than untreated rats sacrificed on the 42nd postoperative day; also there was less necrotic debris in the femoral heads of the treated rats. There were no differences in the severity of the degenerative changes of the articular cartilage of the treated and untreated rats. Exposure of rats to hyperbaric oxygen does not preserve tissue viability after all arteries supplying the femoral head are severed. Yet, resulting in an increased oxygen tension of the tissues, it seems to provide the optimal settings for reparative processes. The results suggest that hyperoxygenation-mediated relief of ischemia enhances the fibroblastic, angioblastic, osteoblastic, and osteoclastic activities such that healing of the rats' necrotic femoral heads is expedited.

Animals↗
PubMed1999

Osteoarthritis-like disorder in rats with vascular deprivation-induced necrosis of the femoral head.

The reparative processes following vascular deprivation-induced necrosis of the femoral head were studied histologically in rats sacrificed 2, 7, 14, 21, 42 and 92 days postoperatively. The blood supply was severed by incision of the periosteum at the neck of the femoral head and transection of the ligamentum teres. Granulation tissue and a well-vascularized fibrous tissue originating from the joint capsule invaded the necrotic marrow spaces. With progressive resorption of the necrotic tissues and osteoneogenesis, both appositional and intramembranous, within the fibrotic intertrabecular spaces, the remodeling process led to a shift of the normal spongy architecture of the femoral head to a compacta-like one. In a few cases, osseous bridges bisected a necrotic physeal cartilage at the latest time intervals. The remodeling was associated with flattening of the femoral heads as well as with degenerative, regenerative and reparative alterations of the articular cartilage. In one of the two femoral heads obtained three months postoperatively, cystic spaces developed in the fibrous subchondral zone. Our findings are consistent with the view that ineffective attempts at restoring the prenecrotic state of the femoral head by replacing the necrotic with viable tissue triggers the collapse of the femoral head. Thickening and condensation of the subchondral bone, leading to increased stiffness of the subchondral zone, result in the osteoarthritis-like disorder. Mimicking the well-known phases of human osteonecrosis, the model readily allows for preclinical studies of therapeutic regimens.

Animals↗
PubMed1998

Vascular deprivation-induced necrosis of the femoral head of the rat. An experimental model of avascular osteonecrosis in the skeletally immature individual or Legg-Perthes disease.

The blood supply of rats' femoral heads was severed by cutting the ligamentum teres and stripping the periostium. Histologically, necrosis of the marrow was apparent on the 2nd postoperative day, necrosis of the bone on the 5th postoperative day and fibrous ingrowth on the 7th postoperative day. During the following 5 weeks, progressive resorption of the intertrabecular necrotic debris and necrotic bony trabeculae and subchondral bone plate and, concurrently, appositional and intramembranous new bone formation resulted in remodeling of the femoral heads. In 2 of 7 femoral heads, replacement of the necrotic bone by viable bone was complete at the 42-day postoperative interval. Also, the articular cartilage of the deformed and flattened femoral heads was undergoing degenerative changes. Reduplicating the pathogenically inferred clinical settings of blood supply deprivation, it is proposed that this model, in a small laboratory animal, satisfies the requirements sought for preclinical studies of treatment modalities of avascular osteonecrosis in man.

Animals↗
PubMed1997

[Postoperative ulnar nerve palsy of the elbow].

Ulnar nerve neuropathy of the elbow is a recognized complication of surgery involving general anesthesia. In 13 patients, aged 21-76 years, ulnar nerve palsy developed at various times and of varying degrees of severity during the postoperative period. Diagnosis was based on clinical and electrophysiological findings. 3 patients had subclinical entrapment of the ulnar nerve. All were treated conservatively by rest, splinting and physical therapy: 10 improved slowly with time and 3 were operated on, but only 1 recovered fully. Preventive measures, such as proper positioning on the operative table, use of elbow pads, avoiding adduction of the arm, pronation of the forearm and prolonged elbow flexion, may reduce the incidence of ulnar nerve palsy. Unfortunately, treatment of established lesions has yielded mixed results.

Adult↗
PubMed1997

External fixation for severe open fractures of the humerus caused by missiles.

OBJECTIVE: To evaluate the use of external fixation of the humerus after missile injuries. DESIGN: Retrospective. SETTING: University medical center. PATIENTS: Twenty-six soldiers with twenty-six open Gustilo type III fractures. INTERVENTIONS: Immediate external fixation. MAIN OUTCOME MEASURES: Clinical, functional, social, and rehabilitation criteria were evaluated. RESULTS: Excellent in fourteen patients (61%), good in four (17%), fair in three (13%), and poor in two (9%). All fractures eventually healed. CONCLUSION: External fixation is the preferred initial treatment for stabilizing severe open missile fractures of the humerus. Its use, together with radical debridement of dead bone, has reduced the incidence of chronic infection and improved the prognosis of vascular repairs. As a result, the rate of morbidity and upper limb amputation has been reduced significantly, compared with our previous experience.

Adult↗
PubMed1996

[External humeral fixation in war injuries].

Type III open fractures of the humerus caused by high energy missiles or shrapnel in 26 male soldiers were treated by external fixation. 12 suffered from associated injuries involving the head and chest, 12 had 14 nerve injuries, and 4 required simultaneous repair of the brachial artery. Results in 19 examined after an average of 6.5 years were excellent in 22%, good in 52%, fair in 16%, and poor in 10%. The aim of external fixation is functional limb salvage. We think high-energy gunshot fractures should be classified as III-d because of the severe damage to the soft tissue, which differs from that of low-velocity, gunshot fractures or farm injuries. We conclude that external fixation is the preferred form of primary stabilization of severe open fractures of the humerus. It has reduced the incidence of chronic infection and has improved the prognosis of vascular repairs. The treatment of the soft tissues, skin coverage, and ultimately reconstructive surgery are facilitated. Early limb function allows for a better final result. For delayed union and pin-tract infection a different definitive method, such as internal fixation or a plaster case, is required.

External Fixators↗
PubMed1992

[Treatment of Pipkin's fracture of the femoral head].

We present 3 cases with Pipkin's fracture of the femoral head, a rare and complicated fracture. 2 were operated on and did well. The third, not operated on, has severe symptoms and most probably will require extensive reconstructive surgery.

Adult↗
PubMed1992

Muscle microcirculatory impairment following acute compartment syndrome in the dog.

Visualization of the intramuscular microcirculation during and after compartmental syndrome was studied by microangiograms and histologic cross sections. A marked reduction in the circulation of the endomysial capillary network was found during compartment tamponade, whereas the perimysium arteriolar system was patent. Revascularization took place by formation of distorted blood vessels accompanied by intramuscular hematomas in muscles 7 and 14 days after the compartment insult. The cross sections show massive fibroblastic activity around blood vessels that caused concealed intramuscular pressure-ischemic contracture resulting in the foci of myofibrillar necrosis seen within normal muscle tissue. The muscle located in the tamponaded compartment profusely bleeds when it is touched, even though its viability is in doubt. The explanation for this clinical observation might be the abnormal intramuscular revascularization that was found in this work.

Acute Disease↗
PubMed1991

Hypertonic mannitol ameliorates intracompartmental tamponade in model compartment syndrome in the dog.

Acute compartment syndrome (ACS) is a devastating complication of rhabdomyolysis caused by muscle tamponade secondary to increased intracompartmental pressure (Pi). ACS requires emergency surgical decompression when Pi greater than 30 mmHg (normal less than 4.0 mmHg) and clinical signs exist. The present study was undertaken to examine whether mannitol which has been used extensively for prevention of acute renal failure in rhabdomyiolysis may also improve muscular hemodynamics in ACS. ACS was produced in dogs by injecting dog plasma into the anterolateral compartment of the hind limb. The Pi was directly monitored. Control dogs received saline, whereas experimental dogs received intravenously 20% mannitol (0.15 ml/min/kg) over a period of 1 h. The initial Pi was set arbitrarily at 100 mm Hg. Following the establishment of ACS, the spontaneous mean decrease in Pi in the control group was 40% of initial value over 60 min (n = 5) versus a decrease of 65%/60 min in the experimental (mannitol) group (n = 7, p less than 0.01). The net mean decompressive effect of mannitol treatments was approximately 28 mm Hg (mean control Pi minus mean experimental Pi at time 60 min). Extrapolated to man with ACS, such a decrease in Pi induced by mannitol theoretically could relieve compartmental tamponade noninvasively.

Angiography↗
PubMed1991

A philosophy of limb salvage in war: use of the fixateur externe.

Over the period 1973-1983, we treated by external fixation 110 severe grade three open or complicated fractures caused in war (minimum follow-up, 7 years). We present our data analyzed according to method, location, and type of fracture. The methods we have evolved over the years are described in detail: primary wound stabilization by fixateur externe; primary radical wound excision, repeated every 48 hours as required, including excision of dead bone; delayed primary vascular soft tissue cover; delayed primary or secondary skeletal and soft tissue reconstruction as dictated by local wound conditions; prophylactic antibiotics and intensive physiotherapy to the joints and muscles of the injured limb and as rapid an ambulation of the patient as possible. The advantages and limitations of external fixation are enumerated. It is possible to avoid the complications of pin tract infection and ring necroses, but care is required to avoid refracture after removal of the apparatus, since the quality of bone healing is not always good with the use of external fixation. External fixation has greatly facilitated the various methods for achieving delayed primary vascular soft tissue cover over severe open fractures, bringing about an improved prognosis; micro-vascular techniques hold great promise for wound cover and skeletal reconstruction. Similarly, the Ilizarov method of bone osteotaxis has opened up new vistas in the treatment of bone mass loss. The latter requires a sophisticated set-up which will not be available in most war zones. In spite of the advances in treatment and in the improved results achieved by modern techniques of wound stabilization, wound soft tissue cover, and bone and soft tissue reconstructions, the temptation to try to salvage useless limbs must be resisted. Amputation, judiciously adjudged and correctly timed, remains one of the most successful forms of treatment in these severe injuries, saving the casualty from a physical and spiritual via dolorosa. Enthusiasm for surgical endeavor must be well tempered with mature judgment and realistic clinical acumen.

Amputation, Surgical↗
PubMed1988

Osteochondritis dissecans of the dome of the talus. Computed tomography scanning in diagnosis and follow-up.

From 1977 through 1985, thirty-two patients were treated for osteochondritis dissecans of the dome of the talus. The diagnosis was established in two-thirds of the patients using ordinary roentgenograms, but it was established in all of them using computed tomography scans. After a mean length of follow-up of about five years, the results of surgical treatment were significantly better than those of conservative treatment. For twenty patients, computed tomography scans were superior to roentgenograms in showing healing of the lesion. We concluded that computed tomography is useful not only for diagnosis--that is, in determining the extent and precise location of the lesion--but also for follow-up.

Adolescent↗