OrthoCAD: digital models for a digital era.

This article describes the use of OrthoCAD--a digital study model capture, assessment and storage system. It is estimated that approximately 10% of orthodontists in USA and Canada now utilize digital study models, and improving technology is making it increasingly popular worldwide. The technology behind digital study models is briefly reviewed. The OrthoCAD system is described, and the advantages and disadvantages of using digital study models are highlighted.

Invisalign: early experiences.

This article describes the Invisalign technique. It is based on the author's personal experience of over 60 cases started in the private practice setting. The technology behind Invisalign and its development is reviewed. The Invisalign clinical technique is described, and the advantages and disadvantages of using Invisalign are highlighted.

Congenital scalp defects and vitreoretinal degeneration: redefining the Knobloch syndrome.

An apparently autosomal recessive syndrome of hereditary vitreoretinal degeneration (VRD) with retinal detachment, high myopia, and congenital encephalocele was described in 1971 by Knobloch and Layer [J Pediatr Ophthalmol 8:181-184]. Clinical confirmation of the presence of encephaloceles was lacking, and no neuropathologic studies were reported. We have evaluated a similarly affected family with 2 sibs with high myopia, VRD, and occipital scalp defects. Histologic examination of the scalp defects showed heterotopic neuronal tissue in both instances. The older girl has had a unilateral retinal detachment. Her other eye and both eyes of the younger sib have so far been treated successfully with prophylactic retinal cryotherapy. Both children have normal to above normal intelligence. The family reported by Knobloch and Layer [1971] and the sibship herein described appear to represent a distinct autosomal recessive trait. Analysis of the associated defects suggests an underlying defect in early cephalic neuroectodermal morphogenesis. Data from these families imply that congenital occipital scalp defects rather than true encephaloceles may, as is true in some cases of Meckel syndrome, accompany Knobloch syndrome. The presence of a congenital midline scalp defect should alert the clinician to possible underlying central nervous system and/or ocular pathology and should lead to consideration of further diagnostic evaluations and prophylactic measures.

Diphtheria-tetanus toxoids-pertussis vaccination does not increase the risk of hospitalization with an infectious illness.

The purpose of this study was to determine whether children hospitalized with a primary diagnosis of infection were more likely than matched controls to have had a diphtheria-tetanus toxoids-pertussis immunization in the 30 days before hospitalization of the case. Cases were less likely than controls to have received an immunization (P = 0.003). They were also less likely to have been breast-fed (P < 0.001) and to have had a well-child care clinic visit (P = 0.01). Cases were significantly more likely to be preterm (< 38 weeks gestation), low birth weight (< 2500 g) and attending day care than their matched nonhospitalized controls (P = 0.003, 0.03 and 0.002, respectively). This study demonstrates no association between receipt of diphtheria-tetanus toxoids-pertussis immunization and subsequent hospitalization for an infectious illness.

Safety and immunogenicity of acellular pertussis vaccine combined with diphtheria and tetanus toxoids in 17- to 24-month-old children.

A double-blind, randomized, controlled trial comparing 4 lots of acellular pertussis-diphtheria tetanus toxoids vaccine (APDT) to whole cell DTP vaccine in 397 children was conducted at 7 clinical centers. Children were immunized at 17 to 24 months of age and sera were obtained pre- and postimmunization. Sera were analyzed for antibody to pertussis antigens (pertussis toxin, filamentous hemagglutinin, with a molecular weight of 69,000 (69k) outer membrane protein and agglutinogens) and to diphtheria and tetanus toxoids. Information concerning local reactions and systemic events was collected daily for 10 days postimmunization. The acellular vaccine produced significantly fewer local reactions than whole cell DTP. Parents reported that drowsiness or fretfulness occurred significantly less often in APDT vaccine recipients compared with whole cell DTP recipients. Fever greater than or equal to 38.3 degrees C occurred in 8% of APDT vaccine recipients and in 15% of whole cell DTP vaccine recipients (P = 0.06). The only significant difference in immune response to pertussis antigens between the two vaccines was for filamentous hemagglutinin (P less than 0.01) for which significantly higher antibody concentrations were found in the APDT vaccine group. We conclude that this APDT vaccine is safe and immunogenic when administered as a booster dose to 18-month-old children.

Central retinal vein occlusion in young adults (papillophlebitis).

We performed a retrospective study of 103 cases of central retinal vein occlusion (CRVO) in young, nondiabetic adults that were followed for at least six months. Of these patients, 64% were men and 36% were women. While visual acuity was usually good, 33 eyes (32%) had a final visual acuity of 20/200 or worse, including 6 eyes (6%) with a final visual acuity of no light perception. Ocular complications included chronic cystoid macular edema, macular pigmentary changes (37%), sheathing of retinal vessels (22%), venous collaterals of the disc (33%), macular hole formation (1%), neovascularization of the disc (1%), retina (1%), and iris (19%), neovascular glaucoma (8%), and vitreous hemorrhage (7%).

Cilioretinal artery occlusion in young adults with central retinal vein occlusion.

Ten patients, all younger than 50 years of age, had a temporal cilioretinal artery occlusion associated with a nonischemic central retinal vein occlusion. On fluorescein angiography, the cilioretinal artery eventually filled in all but one eye. The cilioretinal artery showed pulsations on fluorescein angiography in five eyes. The central retinal vein occlusion eventually resolved and the fundus assumed a normal appearance in all nine of the followed cases. Eight of nine eyes that underwent follow-up examination had final visual acuity of 20/30 or better. The occlusion of the central retinal vein produces an elevation of intraluminal capillary pressure because the central retinal artery continues to pump blood into the retina. Because the perfusion pressure of the cilioretinal artery is lower than the central retinal artery, it becomes relatively occluded. The prognosis for these patients is generally good unless the entire parafoveal capillary net is affected by the cilioretinal artery that is occluded.

AIDS in primary care: a report from the Ambulatory Sentinel Practice Network.

BACKGROUND: Despite the importance of the epidemic of acquired immune deficiency syndrome (AIDS), little is known about the incidence and prevalence of AIDS in the patient population of primary care physicians. This study was designed as an initial step in evaluating the impact of this disease on primary care practices. METHODS: We conducted a survey to characterize the AIDS cases in the Ambulatory Sentinel Practice Network (ASPN). ASPN is a practice-based primary care research network. In 1987 it was composed of 65 practices and 193 clinicians serving approximately 270,000 patients in the United States and Canada. Clinicians representing each practice were asked to report the number of AIDS patients that their practice cared for between January 1982 and December 1987. They were further asked to characterize relevant data for these patients. RESULTS: Thirty-nine prevalent cases of AIDS were reported in ASPN from January 1982 through December 1987. Seventy-nine percent of the patients were male, 15 to 44 years of age; three patients (7.6%) were female; and all cases had at least one risk factor for AIDS. An expected number of cases for the 194,973 patients of 47 practices was calculated using age-sex register data and nationally based rates from 1986. The projected number, 13, corresponded with the number of AIDS cases, 11 and 15, reported from ASPN practices in 1986 and 1987, respectively. CONCLUSIONS: This survey suggests that AIDS is at least as prevalent in the primary care practices in ASPN as predicted using national estimates, and may, in fact, be more prevalent. Primary care clinicians need to be prepared to assume a major role in addressing the AIDS epidemic.

Absence of interferon in sera of patients with Kawasaki syndrome.

We measured serum interferon concentrations in 42 patients with Kawasaki syndrome. The children ranged in age from 7 months to 6 years. All acute sera were obtained within 12 days of the onset of fever. Convalescent sera (illness day 19 to 56) were available from 25 of 42 patients. Sera were also obtained from 40 controls ranging in age from 2 months to 12 years. Control sera included healthy children (n = 14), children with bacterial infection (n = 10) and children with viral infection (n = 16). Sera were coded and interferon concentrations were measured blindly using human diploid fibroblast cell monolayers challenged with 10(4) plaque-forming units of vesicular stomatitis virus. Specimens from 10 of 16 patients with viral infection were positive for interferon. Three of 10 patients with bacterial infection had detectable serum interferon. No interferon was detected in specimens from the 14 healthy control children or the 42 children with Kawasaki syndrome. Despite the use of a sensitive assay we were unable to detect interferon in the sera of patients with Kawasaki syndrome.

Purtscher's-like retinopathy after childbirth.

Severe bilateral visual loss attributable to multiple retinal arteriolar occlusions occurred in four young women within 24 hours after childbirth. In two patients, labor was complicated by preeclampsia requiring cesarean section. One patient was suffering from pancreatitis. None had connective tissue disease or antecedent trauma. Ophthalmoscopy and fluorescein angiography revealed evidence of multiple superficial peripapillary and macular patches of ischemic retinal whitening simulating Purtscher's retinopathy. By 8 weeks, the white patches were resolving in all eyes and visual acuity had significantly improved in three of the four patients. The pathogenesis of this disorder is unknown but may involve arteriolar obstruction by complement-induced leukoemboli formed during parturition.

Antigenic recognition by intravenous gamma-globulin of selected bacteria isolated from throats of patients with Kawasaki syndrome.

Kawasaki syndrome (KS) or mucocutaneous lymph node syndrome is an acute febrile exanthematous illness of unknown etiology. Therapy with intravenous gamma-globulin (IVGG) results in rapid defervescence, disappearance of signs and symptoms of inflammation and prevention of coronary artery aneurysms. We hypothesized that IVGG might neutralize a bacterial toxin produced by a staphylococcus or streptococcus present in the nasopharynx. We further speculated that this toxin might be detectable in serum or urine of patients. The goal of this work was to identify microbial antigens in different materials taken from patients with a clinical diagnosis of KS. We tested 23 aerobic bacterial isolates from throat cultures from 15 patients with KS, acute serum from 121 patients and 38 acute urine specimens from patients with KS. The patients ranged in age from 1 to 6 years. Specimens were tested in a standard system of counterimmunoelectrophoresis and reacted against IVGG prepared in a 25% solution. Ten of 23 aerobic bacteria (43.5%) isolated from throat cultures demonstrated a precipitation reaction with IVGG. Counterimmunoelectrophoresis testing of IVGG against acute serum and acute urine specimens was uniformly negative. IVGG contains precipitating antibody against a limited number of aerobic throat organisms. It is possible that antigenic products of one of these bacteria may be involved in the pathogenesis of KS.

Phase II study of fenretinide (N-[4-hydroxyphenyl]retinamide) in advanced breast cancer and melanoma.

Retinoids, the natural and synthetic analogs of vitamin A, are growth-inhibiting and differentiation-inducing agents and show clinical promise as chemopreventive and antineoplastic agents. Fenretinide, a new synthetic retinoid, has antitumor activity in certain in vitro and in vivo model systems and was relatively nontoxic in phase I trials. Based on these data, we designed a phase II study of Fenretinide involving 31 patients with advanced breast cancer [15] and melanoma [16], two cancers shown to be responsive to this agent in preclinical models. Fenretinide was inactive in patients with advanced disease. Toxicity was mild, and reversible. Mucocutaneous side effects occurred in 16 (52%) patients. Nyctalopia developed in three patients one of whom developed decreased B-wave amplitude of the scotopic electroretinogram. The minimal toxicity and significant activity in preclinical studies make this an attractive agent for future breast cancer chemoprevention studies.

Effect of intravenous immune globulin on the coagulopathy of Kawasaki syndrome.

We studied the effects of immune globulin and aspirin versus aspirin alone on platelet count, platelet activation, and factor-mediated coagulation in patients with Kawasaki syndrome. Coagulation tests were performed on the day of admission to the study and 4 to 6 days later. Twenty-three patients were enrolled; 12 received immune globulin intravenously plus aspirin, and 11 received aspirin alone. At initiation of the study the groups were comparable with regard to age, sex, race, and time from onset of illness to study entry. Coagulation values were similar at entry with the exception that the aspirin group had a geometric mean platelet count that was higher than the platelet count in the aspirin-immune globulin group (p = 0.02). Four days after entry there were no significant differences between the two groups in any coagulation studies. Although the immune globulin preparation used has been effective in reducing the prevalence of coronary artery aneurysms, it appears to have no early effect on reduction of platelet activation or other measures of coagulopathy. The mechanism of action of immune globulin in patients with Kawasaki syndrome remains to be elucidated.

A subsidized perinatal care program in a rural Colorado county.

A large number of medically indigent women in rural areas currently receive little or no prenatal care, raising major concerns regarding perinatal health. In Colorado, subsidized prenatal and labor/delivery programs have been instituted to address this problem. This article describes the implementation of two programs in one rural county. In these rural programs, private physicians, health department personnel, and social work staff at the local hospital collaborate to provide financial assistance, comprehensive health education, and quality medical care for eligible pregnant women. The identified benefits and barriers unique to the provision of quality perinatal care in rural settings are discussed.

Reimmunization of children immunized at 18 months of age with Haemophilus influenzae type b vaccine.

We studied the response to reimmunization at 36 months of age with Haemophilus influenzae type b (Hib) polyribosylribitol phosphate (PRP) capsular polysaccharide vaccine. Children enrolled in the study had previously received PRP or PRP plus diphtheria and tetanus toxoids with pertussis vaccine at 18 months of age. A control group of children, who received a first dose at 36 months of age, was also studied. Ninety-five percent of children receiving a second dose of vaccine had a postimmunization anti-capsular antibody level of greater than or equal to 1 microgram/mL. In comparison, 70% of 36-month-old children who received their first dose of PRP had a postimmunization level greater than or equal to 1 microgram/mL (P = 0.09). The geometric mean titer at 37 months of age was 8.64 micrograms/mL in children who had received two doses of PRP vaccine, compared with 2.19 micrograms/mL in the group who received only one dose of PRP at 36 months of age (P = 0.04). We conclude that infants immunized at 17 to 19 months of age with PRP had an excellent immunologic response to reimmunization at 36 months of age.

Kawasaki syndrome and house dust mite exposure.

We investigated exposure to house dust mites and freshly cleaned carpets in patients with Kawasaki syndrome (KS) who resided in Denver, CO. House dust samples were analyzed for mites (Dermatophagoides pteronyssinus and Dermatophagoides farinae) and convalescent sera were assayed for immunoglobulin G antibody to mite antigen. House dust samples from case and neighborhood control homes showed no difference in the prevalence of mites. Fewer than 10% of dust samples from either group revealed evidence of live or dead mites. Nine of 18 (50%) children with KS had a prior history of exposure to freshly cleaned rugs within the 45 days of the onset of KS compared with 3 of 11 (27%) neighborhood controls. There was no difference in mean anti-mite antibody concentrations between convalescent sera from KS cases and sera from pediatric hospitalized controls. We conclude that in Denver KS can occur in the absence of significant mite exposure as defined by environmental studies or serologic means.